Added "CI secret variables" per @axil.

doc/raketasks/backup_restore.md

@@ -15,9 +15,9 @@ another is through backup restore.
 
 To restore a backup, you will also need to restore `/etc/gitlab/gitlab-secrets.json`
 (for omnibus packages) or `/home/git/gitlab/.secret` (for installations
-from source). This file contains the database encryption key used
-for two-factor authentication. If you fail to restore this encryption key file
-along with the application data backup, users with two-factor
+from source). This file contains the database encryption key and CI secret
+variables used for two-factor authentication. If you fail to restore this
+encryption key file along with the application data backup, users with two-factor
 authentication enabled will lose access to your GitLab server.
 
 ## Create a backup of the GitLab system