Add English <En> as target language to our translation template.

This workaround reduces the necessary steps to translate and use pluralised strings.

It fixes following errors while handling the translation template:
1.
``lupdate src -recursive -noobsolete -extensions cpp,h,ui -ts res/translations/mixxx.ts``

Previously completes with error message
``
Removed plural forms as the target language has less forms.
If this sounds wrong, possibly the target language is not set or recognized.
``
We had to manually add an additional <numerusform> key to any pluralised string in the template,
see https://github.com/mixxxdj/mixxx/wiki/internationalization#updating-translation-templates

2.
``tx push -s``
Previously failed on Transifex with ``English pluralized strings should contain 2 plurals``

1 files changed, 41 insertions, 21 deletions

diff --git a/res/translations/mixxx.ts b/res/translations/mixxx.ts
index ae88b77094..8c123d7545 100644
--- a/res/translations/mixxx.ts
+++ b/res/translations/mixxx.ts
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!DOCTYPE TS>
-<TS version="2.1" sourcelanguage="en">
+<TS version="2.1" language="en" sourcelanguage="en">
 <context>
     <name>:</name>
     <message>
@@ -13858,14 +13858,16 @@ Use this to change only the effected (wet) signal with EQ and filter effects.</s
         <location filename="../../src/widget/wtrackmenu.cpp" line="904"/>
         <source>Importing metadata of %n track(s) from file tags</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="936"/>
         <source>Marking metadata of %n track(s) to be exported into file tags</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message>
@@ -13915,126 +13917,144 @@ Use this to change only the effected (wet) signal with EQ and filter effects.</s
         <location filename="../../src/widget/wtrackmenu.cpp" line="1200"/>
         <source>Scaling BPM of %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="1230"/>
         <source>Locking BPM of %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="1231"/>
         <source>Unlocking BPM of %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="1260"/>
         <source>Setting color of %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="1308"/>
         <source>Resetting play count of %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="1333"/>
         <source>Resetting beats of %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="1356"/>
         <source>Clearing rating of %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="1385"/>
         <source>Removing main cue from %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="1395"/>
         <source>Removing outro cue from %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="1405"/>
         <source>Removing intro cue from %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="1415"/>
         <source>Removing loop cues from %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="1425"/>
         <source>Removing hot cues from %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="1447"/>
         <source>Resetting keys of %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="1469"/>
         <source>Resetting replay gain of %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="1500"/>
         <source>Resetting waveform of %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="1554"/>
         <source>Resetting all performance metadata of %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="1662"/>
         <source>Setting cover art of %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
     <message numerus="yes">
         <location filename="../../src/widget/wtrackmenu.cpp" line="1686"/>
         <source>Reloading cover art of %n track(s)</source>
         <translation type="unfinished">
-            <numerusform></numerusform><numerusform></numerusform>
+            <numerusform></numerusform>
+            <numerusform></numerusform>
         </translation>
     </message>
 </context>