Core: Fix more warnings

--HG--
branch : trunk

src/server/scripts/Examples/example_creature.cpp

@@ -271,7 +271,7 @@ class example_creature : public CreatureScript
             return true;
         }
 
-        bool OnGossipSelect(Player* player, Creature* creature, uint32 sender, uint32 action)
+        bool OnGossipSelect(Player* player, Creature* creature, uint32 /*sender*/, uint32 action)
         {
             if (action == GOSSIP_ACTION_INFO_DEF+1)
             {