Core/Units: Removed spline speed limit for MoveJumpWithGravity

Port From (https://github.com/TrinityCore/TrinityCore/commit/96295cfc5fdd6790313eda694da99ee661f3c0f0)

Source/Game/Movement/MotionMaster.cs

@@ -812,6 +812,7 @@ namespace Game.Movement
                 init.SetParabolicVerticalAcceleration(gravity, 0);
                 init.SetUncompressed();
                 init.SetVelocity(speedXY);
+                init.SetUnlimitedSpeed();
                 if (hasOrientation)
                     init.SetFacing(pos.GetOrientation());
                 if (spellEffectExtraData != null)

Source/Game/Movement/MoveSplineInit.cs

@@ -283,6 +283,8 @@ namespace Game.Movement
 
         public void SetOrientationFixed(bool enable) { args.flags.SetUnsetFlag(SplineFlag.OrientationFixed, enable); }
 
+        public void SetUnlimitedSpeed() { args.flags.SetUnsetFlag(SplineFlag.UnlimitedSpeed, true); }
+
         public void MovebyPath(Vector3[] controls, int path_offset = 0)
         {
             args.path_Idx_offset = path_offset;