The current state of lxc-dnsmasq starts it after the network
subsystem is started (but not necessarily up) and it could
possibly start after lxc. This changes things to reflect how
lxc-net upstream systemd file sets up dependencies[1].
[1]: https://github.com/lxc/lxc/blob/master/config/init/systemd/lxc-net.service.in
Change-Id: If378446333dd09e378b3acd297c58fd59ce04789