lxc: reconnect to network after host network restart
In case of network settings changes in LAN, bridge will be restarted and lxc guests will be detached from that bridge.
This could be partially fixed by lxc-hotplug (reattach network lxc interfaces to bridge), but it won't help if network setting changes. In that case we should somehow trigger network reload in lxc guests too to make sure that they will reconnect to newly configured network.
Complement issue to #343 (closed)