Update warden after patch gets merged

Warden would sometimes throw :warden to soon. Causing responses in tests not to be created.

This was the case in https://gitlab.com/gitlab-org/gitlab-ce/issues/40093.

When this pull request gets merged, we will need to update warden, so we can update spec/requests/openid_connect_spec.rb to check the response instead of checking the error raised.

/cc @rymai