Reworking the way vips are handled in get_lb_endpoints (part 3)

* part 1: https://github.com/rcbops-cookbooks/haproxy/commit/eb8f7c95bc996f24178cd600ae3545f492c0c16a
* part 2: https://github.com/rcbops-cookbooks/openstack-ha/commit/20a54462f89e408b70a526d43090939b3ca1f85f