case 4670 initial changes

Program.cs

@@ -1,19 +1,14 @@
-using Microsoft.AspNetCore;
-using Microsoft.AspNetCore.Hosting;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Hosting;
 
 namespace contact
 {
     public class Program
     {
-        public static void Main(string[] args)
-        {
-            CreateWebHostBuilder(args).Build().Run();
-        }
-
-        public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
-            WebHost.CreateDefaultBuilder(args)
-                .UseUrls("http://*:3002")//only this port works with nginx proxy
-                //.UseUrls("http://localhost:3002")//this doesn't work with nginx proxy
-                .UseStartup<Startup>();
+        public static void Main(string[] args) =>
+            Host.CreateDefaultBuilder(args)
+                .ConfigureWebHostDefaults(web => web.UseStartup<Startup>())
+                .Build()
+                .Run();
     }
 }