#1 Cuirass Guix service hangs when network is down.

When network isn't up yet at cuirass service start, or goes down for a moment, the url fetching fails and cuirass service stays hanged and needs to be restarted. Reported by Mathieu OTHACEHE <m.othacehe@gmail.com> here: https://lists.gnu.org/archive/html/guix-devel/2017-01/msg01790.html

fixed by commit abd52046d5eefe9b7be8bc8ba04b2489cbe59ca5.