Sign-up by mail does not work from gitlab.rb
ZD: https://gitlab.zendesk.com/agent/tickets/43009
Please note this one too: enable open server on mattermost is not correctly set up from gitlab rb. You can enable sign up by mail but no one can register when the administration can not get in. So recommendation is to allow configuration of enable open server from gitlab rb.
Also, please note that when you to try to create users from the command line tool of mattermost it hangs indefinitely after reading confusion.json and En.json. I did a truss on it but it only hangs. No clear open port or file.