refact

Models/ErrorViewModel.cs

@@ -1,4 +1,5 @@
 using System;
+using IdentityServer4.Models;
 
 namespace nuget_host.Models
 {
@@ -7,5 +8,18 @@ namespace nuget_host.Models
         public string RequestId { get; set; }
 
         public bool ShowRequestId => !string.IsNullOrEmpty(RequestId);
+
+
+        public ErrorViewModel()
+        {
+        }
+
+        public ErrorViewModel(string error)
+        {
+            Error = new ErrorMessage { Error = error };
+        }
+
+        public ErrorMessage Error { get; set; }
+        
     }
 }