Update Program.cs

Solving the problems that project cannot be run on IIS.

test/Ocelot.ManualTest/Program.cs

@@ -16,8 +16,8 @@ namespace Ocelot.ManualTest
 
             builder.UseKestrel()
                 .UseContentRoot(Directory.GetCurrentDirectory())
+                .UseIISIntegration()
                 .UseStartup<Startup>();                
-
             var host = builder.Build();
 
             host.Run();