Restore hack for instance dungeon difficulty reset exploit.

--HG--
branch : trunk

src/game/Group.cpp

@@ -1499,7 +1499,9 @@ void Group::SetDungeonDifficulty(Difficulty difficulty)
             continue;
         player->SetDungeonDifficulty(difficulty);
         player->SendDungeonDifficulty(true);
-        //send player to recall positio nis a dungeon (to avoid an exploit)
+        // Send player to recall position is a dungeon (to avoid an exploit)
+        if (sMapStore.LookupEntry(player->GetMap()->IsDungeon()))
+            player->TeleportTo(player->m_recallMap, player->m_recallX, player->m_recallY, player->m_recallZ, player->m_recallO);
     }
 }