After LXC version 3, some settings were changed to new names. Same as
network. LXC introduced network indexes and changed IPv{4,6} addresses
fields. Before, users should only pass `lxc.network.ipv4` to define an
IPv4 address. Now, on version 3, users need to pass
`lxc.net.X.ipv4.address` to specify the same thing. Same for IPv6.
Signed-off-by: Julio Faracco <jcfaracco@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>