Allow to configure smtp and sendmail in gitlab.yml
Created by: jirutka
Reopening #8800.
TODO:
-
Make it backward compatible with existing smtp_settings.rb(see comments here and here). -
Create doc/update/7.10-to-7.11.mdand add instructions to migrate email settings fromsmtp_settings.rbtogitlab.yml. -
Mention this change in the changelog. -
Update Omnibus package → omnibus-gitlab#555.