fixed a bug regarding panels when starting a new game

cicaprojekt/ApplicationFrame.java

@@ -48,6 +48,7 @@ public class ApplicationFrame implements Runnable
     public void backToMapSelection() {
         jframe.remove(gamepanel);
         initMapselector();
+        jframe.remove(mapselectorpanel);
         jframe.add(mapselectorpanel);
         jframe.revalidate();
     }