Removed unused using

Author: linkdotnet

src/LinkDotNet.Blog.Web/AppConfigurationFactory.cs

@@ -1,5 +1,4 @@
-using System;
-using LinkDotNet.Blog.Domain;
+using LinkDotNet.Blog.Domain;
 using LinkDotNet.Blog.Web.Shared.Services;
 using Microsoft.Extensions.Configuration;