Remove unused class

osu.Game/Screens/OnlinePlay/Multiplayer/Match/ConfirmAbortDialog.cs

@@ -1,15 +0,0 @@
-// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
-// See the LICENCE file in the repository root for full licence text.
-
-using osu.Game.Overlays.Dialog;
-
-namespace osu.Game.Screens.OnlinePlay.Multiplayer.Match
-{
-    public partial class ConfirmAbortDialog : DangerousActionDialog
-    {
-        public ConfirmAbortDialog()
-        {
-            HeaderText = "Are you sure you want to abort the match?";
-        }
-    }
-}