mysql module add ssl connection support (#5610)

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##### Summary

Fixes: #5608 

Add ssl connection support to MySQLService

> python-mysqlclient connection

```
        :param dict ssl:                                                                            
            dictionary or mapping contains SSL connection parameters;                               
            see the MySQL documentation for more details                                            
            (mysql_ssl_set()).  If this is set, and the client does not                             
            support SSL, NotSupportedError will be raised.
```

[SSL connection parameters:](https://dev.mysql.com/doc/refman/5.6/en/mysql-ssl-set.html)

 - **key**: The path name of the client private key file.
 - **cert**: The path name of the client public key certificate file.
 - **ca**: The path name of the Certificate Authority (CA) certificate file. This option, if used, must specify the same certificate used by the server.
 - **capath**: The path name of the directory that contains trusted SSL CA certificate files.
 - **cipher**: The list of permitted ciphers for SSL encryption.

##### Component Name

[`collectors/python.d.plugin/python_modules/bases/FrameworkServices/MySQLService`](https://github.com/netdata/netdata/blob/master/collectors/python.d.plugin/python_modules/bases/FrameworkServices/MySQLService.py)

___

@woosley please test it

```yaml
tcp:
  name     : 'local'
  user     : 'user'
  pass     : 'pass'
  host     : 'localhost'
  port     : '3306'
  ssl:
    key:   'path/to/key'
    cert:  'path/to/cet'
    ca:    'path/to/ca'
```

1 files changed, 6 insertions, 0 deletions

diff --git a/collectors/python.d.plugin/python_modules/bases/FrameworkServices/MySQLService.py b/collectors/python.d.plugin/python_modules/bases/FrameworkServices/MySQLService.py
index 9a694aa825..a09041ca48 100644
--- a/collectors/python.d.plugin/python_modules/bases/FrameworkServices/MySQLService.py
+++ b/collectors/python.d.plugin/python_modules/bases/FrameworkServices/MySQLService.py
@@ -44,6 +44,7 @@ class MySQLService(SimpleService):
                 properties['user'] = conf['user']
             if conf.get('pass'):
                 properties['passwd'] = conf['pass']
+
             if conf.get('socket'):
                 properties['unix_socket'] = conf['socket']
             elif conf.get('host'):
@@ -51,9 +52,14 @@ class MySQLService(SimpleService):
                 properties['port'] = int(conf.get('port', 3306))
             elif conf.get('my.cnf'):
                 if MySQLdb.__name__ == 'pymysql':
+                    # TODO: this is probablt wrong, it depends on version
                     self.error('"my.cnf" parsing is not working for pymysql')
                 else:
                     properties['read_default_file'] = conf['my.cnf']
+
+            if conf.get('ssl'):
+                properties['ssl'] = conf['ssl']
+
             if isinstance(extra_conf, dict) and extra_conf:
                 properties.update(extra_conf)