Core/ObjectMgr: Move some npc_spellclick_spells and vehicle_accessory related errors to startup instead of post-startup runtime

src/server/game/Entities/Unit/Unit.h

@@ -622,7 +622,7 @@ enum NPCFlags
     UNIT_NPC_FLAG_AUCTIONEER            = 0x00200000,       // 100%
     UNIT_NPC_FLAG_STABLEMASTER          = 0x00400000,       // 100%
     UNIT_NPC_FLAG_GUILD_BANKER          = 0x00800000,       // cause client to send 997 opcode
-    UNIT_NPC_FLAG_SPELLCLICK            = 0x01000000,       // cause client to send 1015 opcode (spell click), dynamic, set at loading and don't must be set in DB
+    UNIT_NPC_FLAG_SPELLCLICK            = 0x01000000,       // cause client to send 1015 opcode (spell click)
     UNIT_NPC_FLAG_PLAYER_VEHICLE        = 0x02000000,       // players with mounts that have vehicle data should have it set
 };
 

src/server/game/Entities/Vehicle/Vehicle.cpp

@@ -248,8 +248,6 @@ void Vehicle::InstallAccessory(uint32 entry, int8 seatId, bool minion, uint8 typ
 
         if (!me->HandleSpellClick(accessory, seatId))
         {
-            sLog->outErrorDb("Vehicle entry %u in vehicle_accessory does not have a valid record in npc_spellclick_spells! Cannot join vehicle.",
-                m_creatureEntry);
             accessory->AddObjectToRemoveList();
             return;
         }