Retry on HTTP error

When there was a 404 error for example it would retry the request, but this should not be the case since it will just come back with the same error. It should only retry when there is a network error.

src/Proyecto26.RestClient/Helpers/HttpBase.cs

@@ -23,7 +23,7 @@ public static IEnumerator CreateRequestAndRetry(RequestHelper options, Action<Re
                         callback(null, response);
                         break;
                     }
-                    else if (!options.IsAborted && retries < options.Retries)
+                    else if (!options.IsAborted && retries < options.Retries && request.isNetworkError)
                     {
                         yield return new WaitForSeconds(options.RetrySecondsDelay);
                         retries++;