Prevent deadlock on container stop failure
Prevent deadlock on container stop failure

Closes #1834

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

Skarlso/lxd,stgraber/lxd,chrisglass/lxd,jsavikko/lxd,akshaykarle/lxd,hallyn/lxd,hallyn/lxd,lxc/lxd,pcdummy/lxd,Skarlso/lxd,ollie314/lxd,jsavikko/lxd,stgraber/lxd,pcdummy/lxd,atxwebs/lxd,hallyn/lxd,jsavikko/lxd,stgraber/lxd,erikmack/lxd,lxc/lxd,stgraber/lxd,Skarlso/lxd,erikmack/lxd,atxwebs/lxd,ollie314/lxd,techtonik/lxd,mjeanson/lxd,lxc/lxd,mjeanson/lxd,ollie314/lxd,lxc/lxd,akshaykarle/lxd,Skarlso/lxd,hallyn/lxd,techtonik/lxd,chrisglass/lxd,stgraber/lxd,hallyn/lxd,stgraber/lxd,lxc/lxd,georghopp/lxd,lxc/lxd,mjeanson/lxd,chrisglass/lxd,atxwebs/lxd,erikmack/lxd,akshaykarle/lxd,techtonik/lxd,georghopp/lxd,georghopp/lxd,lxc/lxd,pcdummy/lxd,hallyn/lxd,stgraber/lxd,atxwebs/lxd