Fix CustomCommandListener NPE

Signed-off-by: yoyosource <yoyosource@nidido.de>

BauSystem_Main/src/de/steamwar/bausystem/features/script/CustomCommandListener.java

@@ -182,6 +182,7 @@ public class CustomCommandListener implements Listener {
     }
 
     private YAPIONObject output(Player p) {
+        if (!playerMap.containsKey(p)) return new YAPIONObject();
         YAPIONObject yapionObject = new YAPIONObject();
         YAPIONMap yapionMap = new YAPIONMap();
         yapionObject.add("", yapionMap);