Add 'void' keyword to parameterless function declaration.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@16861 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

ffserver.c

@@ -4441,7 +4441,7 @@ static void handle_child_exit(int sig)
     need_to_start_children = 1;
 }
 
-static void opt_debug()
+static void opt_debug(void)
 {
     ffserver_debug = 1;
     ffserver_daemon = 0;