early exit for pets attacking a null target

src/engine/gameManager/CombatManager.java

@@ -124,7 +124,7 @@ public enum CombatManager {
                 return;
 
             //check if this slot is on attack timer, if timer has passed clear it, else early exit
-            if(attacker.getTimers().containsKey("Attack"+slot.name()))
+            if(attacker.getTimers() != null && attacker.getTimers().containsKey("Attack"+slot.name()))
                 if(attacker.getTimers().get("Attack"+slot.name()).timeToExecutionLeft() <= 0)
                     attacker.getTimers().remove("Attack"+slot.name());
                 else