Fix build

Author: javiercn

src/Components/Endpoints/src/RazorComponentEndpointInvoker.cs

@@ -3,7 +3,6 @@
 
 using System.Buffers;
 using System.Diagnostics;
-using System.Net.Http;
 using System.Text;
 using System.Text.Encodings.Web;
 using Microsoft.AspNetCore.Antiforgery;