Make puma works with GitLab to 5.1 final.

Puma now starts correctly.
As it stands, admin login isn't possible because LDAP is activated.
https://github.com/gitlabhq/gitlabhq/issues/3672 "Other sign-in" broken when ldap is enabled in 5.1
https://github.com/gitlabhq/gitlabhq/pull/3469 "Change text_field to :login from :email in LDAP login page"
https://github.com/gitlabhq/gitlabhq/pull/3646 "customizable LDAP attribute mapping"

M  .ports.ini:
  Add '@PORT_HTTPS_GITLAB_PUMA@' ssl port for puma to listen to.
M  gitlab/gitlabd:
  Use the right option for puma: '-C' (not '-c')
  Start puma, and make sure sidekiq actually starts
M  gitlab/install_or_update_gitlab.sh.tpl:
  Start 'demod' before any bundle exec checks
M  gitlab/puma.rb.tpl:
  bind 'ssl://@FQN@:@PORT_HTTPS_GITLAB_PUMA@'
M  gitlab/sidekiqd:
  Add markers for sidekiq states