Remove double cast when one will do

Author: haacked

RestSharp/Http.Async.cs

@@ -118,7 +118,8 @@ private HttpWebRequest GetStyleMethodInternalAsync(string method, Action<HttpRes
 		private HttpResponse CreateErrorResponse(Exception ex)
 		{
 			var response = new HttpResponse();
-			if (ex is WebException && ((WebException)ex).Status == WebExceptionStatus.RequestCanceled)
+			var webException = ex as WebException;
+			if (webException != null && webException.Status == WebExceptionStatus.RequestCanceled)
 			{
 				response.ResponseStatus = _timeoutState.TimedOut ? ResponseStatus.TimedOut : ResponseStatus.Aborted;
 				return response;