lxd/containers: Log auto-start errors
lxd/containers: Log auto-start errors

As auto-start isn't user triggered we should log something in the daemon log.

Closes #4054

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

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