Fix fleeing speed to 66% run speed

Port From (https://github.com/TrinityCore/TrinityCore/commit/d095d4afe95125bba64312025528a2c4aab157e0)

Source/Game/Entities/Creature/Creature.cs

@@ -713,7 +713,6 @@ namespace Game.Entities
                 var creature = searcher.GetTarget();
 
                 SetNoSearchAssistance(true);
-                UpdateSpeed(UnitMoveType.Run);
 
                 if (!creature)
                     SetControlled(true, UnitState.Fleeing);
@@ -1810,13 +1809,8 @@ namespace Game.Entities
 
                 SetMountDisplayId(0); // if creature is mounted on a virtual mount, remove it at death
 
-                SetActive(false);
-
-                if (HasSearchedAssistance())
-                {
-                    SetNoSearchAssistance(false);
-                    UpdateSpeed(UnitMoveType.Run);
-                }
+                SetActive(false);                
+                SetNoSearchAssistance(false);
 
                 //Dismiss group if is leader
                 if (m_formation != null && m_formation.GetLeader() == this)

Source/Game/Entities/Unit/Unit.Combat.cs

@@ -400,16 +400,8 @@ namespace Game.Entities
             // reset only at real combat stop
             Creature creature = ToCreature();
             if (creature != null)
-            {
                 creature.SetNoCallAssistance(false);
 
-                if (creature.HasSearchedAssistance())
-                {
-                    creature.SetNoSearchAssistance(false);
-                    UpdateSpeed(UnitMoveType.Run);
-                }
-            }
-
             SendMeleeAttackStop(victim);
             return true;
         }

Source/Game/Entities/Unit/Unit.Movement.cs

@@ -543,10 +543,6 @@ namespace Game.Entities
             Creature creature = ToCreature();
             if (creature != null)
             {
-                // for creature case, we check explicit if mob searched for assistance
-                if (ToCreature().HasSearchedAssistance())
-                    speed *= 0.66f;                                 // best guessed value, so this will be 33% reduction. Based off initial speed, mob can then "run", "walk fast" or "walk".
-
                 if (creature.HasUnitTypeMask(UnitTypeMask.Minion) && !creature.IsInCombat())
                 {
                     if (GetMotionMaster().GetCurrentMovementGeneratorType() == MovementGeneratorType.Follow)