Updated openstack/openstack
Project: openstack/nova  f6bf4f6b6b1757be83003612b32afbc771dfb7ff
null
Refactor CIDR field to use netaddr.IPNetwork

This makes the CIDR field become the IPNetwork field (and associate
versioned fields). It also uses the netaddr.IPNetwork class, which
is what should have been done in the first place.

Wire format is unchanged, so we can make this without any version
bumps or upgrade impact.

Related to blueprint nova-network-objects

Change-Id: I1a3ab6a5f4c624f3da0ab1c78c75c6f1e474541f