mgr/cephadm: try to get FQDN for configuration files
Reviewed-by: Adam King <adking@redhat.com> Reviewed-by: Michael Fritch <mfritch@suse.com> Reviewed-by: Patrick Seidensal <pseidensal@suse.com> Reviewed-by: Paul Cuzner <pcuzner@redhat.com> Reviewed-by: Volker Theile <vtheile@suse.com>