Update 04-refactor-state-management.md (#262)

Needed to update text to match code change.

docs/04-refactor-state-management.md

@@ -20,7 +20,7 @@ public static async Task Main(string[] args)
     var builder = WebAssemblyHostBuilder.CreateDefault(args);
     builder.RootComponents.Add<App>("app");
 
-    builder.Services.AddBaseAddressHttpClient();
+    builder.Services.AddTransient(sp => new HttpClient { BaseAddress = new Uri(builder.HostEnvironment.BaseAddress) });
     builder.Services.AddScoped<OrderState>();
 
     await builder.Build().RunAsync();