Follow-up from "fix group without owner after transfer"

References

Merged MR that introduced documentation requiring review: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/25573

Related issue(s): https://gitlab.com/gitlab-org/gitlab-ce/issues/58086

Further Details

See the discussion at https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/25573#note_146466353.