Gitlab with Let's Encrypt certificate: upgrade your ACME client to ACMEv2

https://gitlab.com/gitlab-org/omnibus-gitlab/issues/4614#note_232009029

Interesting dilemma. We've upgraded the ACME client in !3420 (merged) in GitLab 12.1, but you're blocked from upgrading until you can get a successful reconfigure.

So you need to upgrade to gitlab >= 12.1

1. Turn off letsencrypt: nano /etc/gitlab/gitlab.rb a few pages down look for: letsencrypt['enable'] = true and set it to false then save

2. Upgrade to latest release of your major version apt-get upgrade gitlab-ee=11.11.8

3. Run gitlab-ctl reconfigure

4. Upgrade to Gitlab 12 apt-get upgrade gitlab-ee

5. Run gitlab-ctl reconfigure

6. Reboot sudo reboot

7. Return letsencrypt['enable'] = true in /etc/gitlab/gitlab.rb

8. Run gitlab-ctl reconfigure

9. Run gitlab-ctl renew-le-certs