Fixed DeleteWindow and allowed it to close.

PcgsInvUi/ViewModels/EditViewModel.cs

@@ -1,5 +1,4 @@
-using System;
-using System.Reactive;
+using System.Reactive;
 using PcgsInvUi.Models;
 using ReactiveUI;
 
@@ -25,4 +24,4 @@ public class EditViewModel : ViewModelBase {
         // Setup OkCommand - all Coin-related properties must be non-whitespace.
         OkCommand = ReactiveCommand.Create(() => { });
     }
-}
+}