Move moving unbuckling to update to avoid an event bus concurrent modification exception (#1509)

Content.Server/GameObjects/EntitySystems/BuckleSystem.cs

@@ -13,34 +13,6 @@ namespace Content.Server.GameObjects.EntitySystems
     [UsedImplicitly]
     public class BuckleSystem : EntitySystem
     {
-#pragma warning disable 649
-        [Dependency] private readonly IMapManager _mapManager;
-#pragma warning restore 649
-
-        /// <summary>
-        ///     Checks if a buckled entity should be unbuckled from moving
-        ///     too far from its strap.
-        /// </summary>
-        /// <param name="moveEvent">The move event of a buckled entity.</param>
-        private void MoveEvent(MoveEvent moveEvent)
-        {
-            if (!moveEvent.Sender.TryGetComponent(out BuckleComponent buckle) ||
-                buckle.BuckledTo == null ||
-                !buckle.BuckleOffset.HasValue)
-            {
-                return;
-            }
-
-            var bucklePosition = buckle.BuckledTo.Owner.Transform.GridPosition.Offset(buckle.BuckleOffset.Value);
-
-            if (moveEvent.NewPosition.InRange(_mapManager, bucklePosition, 0.2f))
-            {
-                return;
-            }
-
-            buckle.TryUnbuckle(buckle.Owner, true);
-        }
-
         public override void Initialize()
         {
             base.Initialize();
@@ -49,8 +21,6 @@ namespace Content.Server.GameObjects.EntitySystems
 
             UpdatesAfter.Add(typeof(InteractionSystem));
             UpdatesAfter.Add(typeof(InputSystem));
-
-            SubscribeLocalEvent<MoveEvent>(MoveEvent);
         }
 
         public override void Update(float frameTime)