Fix Avalonia not liking to be included twice.

Aaru.Gui/Main.cs

@@ -0,0 +1,17 @@
+using Avalonia;
+using Avalonia.Dialogs;
+using Avalonia.Logging.Serilog;
+using Avalonia.ReactiveUI;
+
+namespace Aaru.Gui
+{
+    public static class Main
+    {
+        public static int Start(string[] args) => BuildAvaloniaApp().StartWithClassicDesktopLifetime(args);
+
+        // Avalonia configuration, don't remove; also used by visual designer.
+        public static AppBuilder BuildAvaloniaApp() => AppBuilder.
+                                                       Configure<App>().UsePlatformDetect().LogToDebug().
+                                                       UseReactiveUI().UseManagedSystemDialogs();
+    }
+}