lxd/images: Specify image type during distribution
lxd/images: Specify image type during distribution

I've run into a cluster where a bunch of VM images were incorrectly
recorded as container images. I believe that a combination of
auto-refresh and distribution is what caused the issue and that this
should fix it.

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

atxwebs/lxd,atxwebs/lxd,atxwebs/lxd,stgraber/lxd,hallyn/lxd,lxc/lxd,stgraber/lxd,stgraber/lxd,hallyn/lxd,stgraber/lxd,hallyn/lxd,stgraber/lxd,lxc/lxd,lxc/lxd,stgraber/lxd,stgraber/lxd,lxc/lxd,lxc/lxd,lxc/lxd,hallyn/lxd,atxwebs/lxd,lxc/lxd,hallyn/lxd,hallyn/lxd