a failed login on custom login URL is no longer on custom URL for 2nd attempt

@etheos has already reported this issue

Almost all the clients for whom I have installed and configured the custom login URL, have complained quite a bit about this issue.

I made a patch to solve this problem.
https://gist.github.com/luistar15/03b592d39f1e2c269d8e22a521f7d427