转移.net core 3.1，为.NET 5做准备

OpenAuth.Identity/Quickstart/Account/ExternalProvider.cs

@@ -0,0 +1,12 @@
+// Copyright (c) Brock Allen & Dominick Baier. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See LICENSE in the project root for license information.
+
+
+namespace OpenAuth.IdentityServer.Quickstart.Account
+{
+    public class ExternalProvider
+    {
+        public string DisplayName { get; set; }
+        public string AuthenticationScheme { get; set; }
+    }
+}