Merge branch 'mailroom-log-shipping' into 'master'

Set svlogd prefix for mailroom

This is needed for usable UDP log shipping (syslog).

See merge request !519

files/gitlab-cookbooks/gitlab/libraries/gitlab.rb

@@ -157,6 +157,7 @@ module Gitlab
         postgresql
         remote-syslog
         gitlab-git-http-server
+        mailroom
         mattermost
       }.each do |runit_sv|
         Gitlab[runit_sv.gsub('-', '_')]['svlogd_prefix'] ||= "#{node['hostname']} #{runit_sv}: "