aspnetboilerplate: httpConfiguration ensureInitialized error?

Hi hikalkan, When i upgrade my project to abp 0.8.0.1, now i got the following exception:

{
"message": "An error has occurred.",
"exception_message": "The object has not yet been initialized. Ensure that HttpConfiguration.EnsureInitialized() is called in the application's startup code after all other initialization code.",
"exception_type": "System.InvalidOperationException",
"stack_trace": "   在 System.Web.Http.Routing.RouteCollectionRoute.get_SubRoutes()\r\n   在 System.Web.Http.Routing.RouteCollectionRoute.GetRouteData(String virtualPathRoot, HttpRequestMessage request)\r\n   在 System.Web.Http.HttpRouteCollection.GetRouteData(HttpRequestMessage request)\r\n   在 System.Web.Http.Dispatcher.HttpRoutingDispatcher.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)\r\n   在 System.Net.Http.DelegatingHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)\r\n   在 Abp.WebApi.Controllers.ResultWrapperHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)\r\n   在 System.Net.Http.DelegatingHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)\r\n   在 System.Web.Http.Owin.PassiveAuthenticationMessageHandler.<SendAsync>d__0.MoveNext()\r\n--- 引发异常的上一位置中堆栈跟踪的末尾 ---\r\n   在 System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)\r\n   在 System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)\r\n   在 System.Web.Http.HttpServer.<SendAsync>d__0.MoveNext()"
}

I have see the issue[https://github.com/aspnetboilerplate/aspnetboilerplate/issues/850], it have fixed by this update, why do I have this error?