Core/Spell: allow SPELL_EFFECT_QUEST_COMPLETE to set a quest to rewarded only if that quest is used as internal flag by the server (has flag 1024 - QUEST_FLAGS_TRACKING).

src/server/game/Spells/SpellEffects.cpp

@@ -4313,8 +4313,8 @@ void Spell::EffectQuestComplete(SpellEffIndex effIndex)
         uint16 logSlot = player->FindQuestSlot(questId);
         if (logSlot < MAX_QUEST_LOG_SIZE)
             player->AreaExploredOrEventHappens(questId);
-        else if (player->CanTakeQuest(quest, false))    // Check if the quest has already been turned in.
-            player->SetRewardedQuest(questId);          // If not, set status to rewarded without broadcasting it to client.
+        else if (quest->HasFlag(QUEST_FLAGS_TRACKING))  // Check if the quest is used as a serverside flag.
+            player->SetRewardedQuest(questId);          // If so, set status to rewarded without broadcasting it to client.
     }
 }