Core/ScriptMgr: Remove incorrect assertion in OnGameObjectDestroyed, and clean up code style (fix by Zor)

--HG--
branch : trunk

src/server/game/Scripting/ScriptMgr.cpp

@@ -822,7 +822,6 @@ uint32 ScriptMgr::GetDialogStatus(Player* player, GameObject* go)
 
 void ScriptMgr::OnGameObjectDestroyed(Player* player, GameObject* go, uint32 eventId)
 {
-    ASSERT(player);
     ASSERT(go);
 
     GET_SCRIPT(GameObjectScript, go->GetScriptId(), tmpscript);