fix cast bug for mob to PC

src/engine/powers/effectmodifiers/HealthEffectModifier.java

@@ -318,7 +318,7 @@ public class HealthEffectModifier extends AbstractEffectModifier {
             AbstractCharacter ac = (AbstractCharacter) awo;
             if (ac.isSit())
                 damage *= 2.5f; // increase damage if sitting
-            if(ac.getObjectType().equals(GameObjectType.PlayerCharacter) && source.equals(ac) == false){
+            if(source.getObjectType().equals(GameObjectType.PlayerCharacter) && source.equals(ac) == false){
                 damage *=  ((PlayerCharacter)source).ZergMultiplier;
             }
         }