if no errors in array, use top-level message for error parsing

Octokit/Helpers/ApiErrorExtensions.cs

@@ -7,7 +7,7 @@ namespace Octokit
         public static string FirstErrorMessageSafe(this ApiError apiError)
         {
             if (apiError == null) return null;
-            if (apiError.Errors == null) return null;
+            if (apiError.Errors == null) return apiError.Message;
             var firstError = apiError.Errors.FirstOrDefault();
             if (firstError == null) return null;
             return firstError.Message;