Core/Movement: ported client control logic updates from 335 branch

src/server/scripts/EasternKingdoms/GrimBatol/grim_batol.cpp

@@ -221,17 +221,13 @@ struct npc_grim_batol_battered_red_drake: public VehicleAI
             me->PlayOneShotAnimKitId(ANIM_KIT_ID_LIFTOFF);
             me->SetAnimationTier(AnimationTier::Fly);
 
-            player->SetMover(me);
             _playerGuid = player->GetGUID();
 
             _events.ScheduleEvent(EVENT_SET_HOVERING, 2s);
             _events.ScheduleEvent(EVENT_PREPARE_BOMBARDMENT, 1s);
         }
         else
-        {
-            player->SetMover(player);
             me->RemoveFlag(UNIT_NPC_FLAGS, UNIT_NPC_FLAG_SPELLCLICK);
-        }
     }
 
     void UpdateAI(uint32 diff) override