Title should hard-coded in https://gitlab.com/gitlab-org/gitlab-ce/blob/714729687fffdeba9a8995b40fc1a2c212e844e9/spec/services/system_note_service_spec.rb#L255
Otherwise the spec could fail if the new title starts with O
, see https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4196/diffs#note_21574136 for details.