Add explicit void to 0-parameter function definitions.

These are the errors output with:
  -Werror=implicit-int -Werror=implicit-function-declaration
  -Werror=int-conversion -Werror=strict-prototypes
  -Werror=old-style-definition

1 files changed, 1 insertions, 1 deletions

diff --git a/background.c b/background.c
index 37a3d335..d3975fa1 100644
--- a/background.c
+++ b/background.c
@@ -467,7 +467,7 @@ static void update_bg_menu (MUTTMENU *menu)
   }
 }
 
-static MUTTMENU *create_bg_menu ()
+static MUTTMENU *create_bg_menu (void)
 {
   MUTTMENU *menu = NULL;
   BACKGROUND_PROCESS *process;