VLCMediaListPlayer: change pause behavior

The pause method is not toggling the pause state anymore. This fixes possible
inconsistencies when the input is paused from an other thread.

Sources/VLCMediaListPlayer.m

@@ -150,7 +150,7 @@
         [self performSelectorInBackground:@selector(pause) withObject:nil];
         return;
     }
-    libvlc_media_list_player_pause(instance);
+    libvlc_media_list_player_set_pause(instance, 1);
 }
 
 - (void)stop