Fix vminterface ip update for dhcp disabled subnet
Fix vminterface ip update for dhcp disabled subnet

Change-Id: I22d64022d419bd8fb8a41fe9d321a33a804bc92b
Depends-On: I42ee88ad7720bef3ade23db1386f6bbdff76b048
Closes-Bug: OPENSTACK-2604

nuagenetworks/nuage-openstack-neutron,nuagenetworks/nuage-openstack-neutron