Fix being able to start pulling something while incapacitated. (#4240)

Content.Shared/MobState/EntitySystems/SharedMobStateSystem.cs

@@ -0,0 +1,22 @@
+using Content.Shared.MobState.Components;
+using Content.Shared.Pulling.Events;
+using Robust.Shared.GameObjects;
+
+namespace Content.Shared.MobState.EntitySystems
+{
+    public class SharedMobStateSystem : EntitySystem
+    {
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            SubscribeLocalEvent<SharedMobStateComponent, StartPullAttemptEvent>(OnStartPullAttempt);
+        }
+
+        private void OnStartPullAttempt(EntityUid uid, SharedMobStateComponent component, StartPullAttemptEvent args)
+        {
+            if(component.IsIncapacitated())
+                args.Cancel();
+        }
+    }
+}