Core/Vehicles:

- Grab correct npc entry from npc_spellclick_spells in case of player vehicle. Fixes DB errors added in my previous changeset
- Allow aura's with SPELL_AURA_CONTROL_VEHICLE to stack if there are enough free seats, even if spellIds are identical.
- Fix a possible infinite loop. Thanks to manuel for spotting

src/server/game/Globals/ObjectMgr.cpp

@@ -790,12 +790,6 @@ void ObjectMgr::CheckCreatureTemplate(CreatureInfo const* cInfo)
     if (cInfo->rangeattacktime == 0)
         const_cast<CreatureInfo*>(cInfo)->rangeattacktime = BASE_ATTACK_TIME;
 
-    if (cInfo->npcflag & UNIT_NPC_FLAG_SPELLCLICK)
-    {
-        sLog->outErrorDb("Creature (Entry: %u) has dynamic flag UNIT_NPC_FLAG_SPELLCLICK (%u) set, it is expected to be set by code handling `npc_spellclick_spells` content.", cInfo->Entry, UNIT_NPC_FLAG_SPELLCLICK);
-        const_cast<CreatureInfo*>(cInfo)->npcflag &= ~UNIT_NPC_FLAG_SPELLCLICK;
-    }
-
     if ((cInfo->npcflag & UNIT_NPC_FLAG_TRAINER) && cInfo->trainer_type >= MAX_TRAINER_TYPE)
         sLog->outErrorDb("Creature (Entry: %u) has wrong trainer type %u.", cInfo->Entry, cInfo->trainer_type);