Conditionally set my_ip
Conditionally set my_ip

local-ipv4 isn't set on the seed vm, causing nova-api to fail to start.

Change-Id: I5a321649b0258bda22c1f257adcb1781d2319df8

openstack/tripleo-image-elements,rdo-management/tripleo-image-elements,radez/tripleo-image-elements,rdo-management/tripleo-image-elements,openstack/tripleo-image-elements,radez/tripleo-image-elements