Core/Creature: Fix creature respawn time in unloaded/inactive grid cells.

Fixes issue 1865.

--HG--
branch : trunk

src/server/game/Entities/Pet/Pet.cpp

@@ -499,7 +499,7 @@ void Pet::Update(uint32 diff)
     {
         case CORPSE:
         {
-            if (getPetType() != HUNTER_PET || m_deathTimer <= diff)
+            if (getPetType() != HUNTER_PET || m_corpseRemoveTime <= time(NULL))
             {
                 Remove(PET_SAVE_NOT_IN_SLOT);               //hunters' pets never get removed because of death, NEVER!
                 return;