Core/DBLayer: Fix a silly error in HandleStableSwapPet (synchronous query in async context). Fixes possible loss of pets when swapping.

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

@@ -805,7 +805,7 @@ void WorldSession::HandleStableSwapPet(WorldPacket & recv_data)
     // find swapped pet slot in stable
     _stableSwapCallback.SetParam(pet_number);
     _stableSwapCallback.SetFutureResult(
-            CharacterDatabase.PQuery("SELECT slot, entry FROM character_pet WHERE owner = '%u' AND id = '%u'",
+            CharacterDatabase.AsyncPQuery("SELECT slot, entry FROM character_pet WHERE owner = '%u' AND id = '%u'",
                 _player->GetGUIDLow(), pet_number)
             );
 }

src/server/shared/Threading/Callback.h

@@ -35,6 +35,7 @@ class QueryCallback
     public:
         QueryCallback() {}
 
+        //! The parameter of this function should be a resultset returned from either .AsyncQuery or .AsyncPQuery
         void SetFutureResult(ACE_Future<Result> value)
         {
             result = value;
@@ -81,6 +82,7 @@ class QueryCallback_2
     public:
         QueryCallback_2() {}
 
+        //! The parameter of this function should be a resultset returned from either .AsyncQuery or .AsyncPQuery
         void SetFutureResult(ACE_Future<Result> value)
         {
             result = value;