Fix not existing Method

FightSystem_Main/src/de/steamwar/fightsystem/listener/PersonalKitCreator.java

@@ -137,7 +137,7 @@ public class PersonalKitCreator extends BasicListener {
     }
 
     private static void useKit(Player player, PersonalKit kit) {
-        kit.setInUse(true);
+        kit.setInUse();
         player.closeInventory();
     }