Better handle rsync errors (subprocesses)
Better handle rsync errors (subprocesses)

Signed-off-by: Stéphane Graber <089afc6d81f66f1168a9849e15660feae286e024@ubuntu.com>

hallyn/lxd,lxc/lxd,hallyn/lxd,lxc/lxd,stgraber/lxd,stgraber/lxd,atxwebs/lxd,hallyn/lxd,Skarlso/lxd,Skarlso/lxd,hallyn/lxd,Skarlso/lxd,jsavikko/lxd,stgraber/lxd,pcdummy/lxd,atxwebs/lxd,erikmack/lxd,jsavikko/lxd,georghopp/lxd,stgraber/lxd,lxc/lxd,lxc/lxd,lxc/lxd,techtonik/lxd,Skarlso/lxd,pcdummy/lxd,stgraber/lxd,hallyn/lxd,georghopp/lxd,hallyn/lxd,stgraber/lxd,erikmack/lxd,techtonik/lxd,georghopp/lxd,atxwebs/lxd,jsavikko/lxd,pcdummy/lxd,erikmack/lxd,techtonik/lxd,mjeanson/lxd,lxc/lxd,mjeanson/lxd,atxwebs/lxd,stgraber/lxd,lxc/lxd,mjeanson/lxd