chore: fix WPF Warning

src/MaaWpfGui/Helper/AppIcon.cs

@@ -43,7 +43,7 @@ public class AppIcon
         catch (Exception)
         {
             throw;
-            return new BitmapImage();
+            // return new BitmapImage();
         }
     }
 

src/MaaWpfGui/WineCompat/FontConfig/Types.cs

@@ -2,6 +2,7 @@
 // MaaWpfGui - A part of the MAA project
 // Copyright (C) 2021 MistEO and Contributors
 // </copyright>
+#pragma warning disable CS0649
 using System;
 using System.Runtime.InteropServices;