Sync config v14.9.0 : Update docs link in mail_room yml section

See upstream merge request
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/81130

Author: kkimurak

assets/runtime/config/gitlabhq/gitlab.yml

@@ -189,7 +189,7 @@ production: &base
 
   ## Reply by email
   # Allow users to comment on issues and merge requests by replying to notification emails.
-  # For documentation on how to set this up, see http://doc.gitlab.com/ce/administration/reply_by_email.html
+  # For documentation on how to set this up, see https://docs.gitlab.com/ee/administration/reply_by_email.html
   incoming_email:
     enabled: {{GITLAB_INCOMING_EMAIL_ENABLED}}