Fix operation cancelled exception when changing visual settings

osu.Game/Skinning/LocalSkinOverrideContainer.cs

@@ -85,12 +85,10 @@ namespace osu.Game.Skinning
         private void load(OsuConfigManager config)
         {
             beatmapSkins = config.GetBindable<bool>(OsuSetting.BeatmapSkins);
-            beatmapSkins.ValueChanged += val => onSourceChanged();
-            beatmapSkins.TriggerChange();
+            beatmapSkins.BindValueChanged(_ => onSourceChanged());
 
             beatmapHitsounds = config.GetBindable<bool>(OsuSetting.BeatmapHitsounds);
-            beatmapHitsounds.ValueChanged += val => onSourceChanged();
-            beatmapHitsounds.TriggerChange();
+            beatmapHitsounds.BindValueChanged(_ => onSourceChanged(), true);
         }
 
         protected override void LoadComplete()

osu.Game/Skinning/SkinReloadableDrawable.cs

@@ -52,5 +52,12 @@ namespace osu.Game.Skinning
         protected virtual void SkinChanged(ISkinSource skin, bool allowFallback)
         {
         }
+
+        protected override void Dispose(bool isDisposing)
+        {
+            base.Dispose(isDisposing);
+
+            skin.SourceChanged -= onChange;
+        }
     }
 }