Add ability to override dynamically openstack proxy addresses

On ci 172.16.10.121 ip is always present as secondary ip on
ens4 interface on prx01 node. This patch modifies openstack_proxy_address
in the way which will allow to override openstack_proxy_address by
ip which is get during node classification.

Change-Id: I203e85bef0ad61fb4e2bd4fb0641c98a236a4b36
Related-Prod: https://mirantis.jira.com/browse/PROD-21674
4 files changed