Core/WorldPacket: Fix the core spamming complaints about CMSG_QUEST_QUERY being sent post-logout

Core/Spells: A little bit of "cleanup"

--HG--
branch : trunk

src/server/game/Server/Protocol/Handlers/QuestHandler.cpp

@@ -264,6 +264,9 @@ void WorldSession::HandleQuestgiverQueryQuestOpcode(WorldPacket & recv_data)
 
 void WorldSession::HandleQuestQueryOpcode(WorldPacket & recv_data)
 {
+    if (!_player)
+        return;
+
     uint32 quest;
     recv_data >> quest;
     sLog.outDebug("WORLD: Received CMSG_QUEST_QUERY quest = %u",quest);