Via Ief0729e51997c3eb1dba679cc40ce7bbf4702bc3 "Adjust shutdown service
management" we dropped support for tripleo_container_manage_systemd_order
let's just remove its use in THT before we remove all traces of it in
tripleo-ansible (via Icc93a5f2d05ef79ff81748435d385cb83b469d4b).
Change-Id: I6fb00e27f8d18ff42f214e5045301c3334d14277