Haproxy config for nova metadata uses ctlplane ip addresses instead of internal_api when using network isolation

Issue

• Haproxy config for nova metadata uses ctlplane ip addresses instead of internal_api when using network isolation, causing deployment to fail at that stage with the following error.

  Warning: Scope(Haproxy::Config[haproxy]): haproxy: The $merge_options parameter will default to true in the next major release. Please review the documentation regarding the implications.
      Error: Could not start Service[nova-api]: Execution of '/usr/bin/systemctl start openstack-nova-api' returned 1: Job for openstack-nova-api.service failed because the control process exited with error code.  See "systemctl status openstack-nova-api.service" and "journalctl -xe" for details. 
      Error: /Stage[main]/Nova::Api/Nova::Generic_service[api]/Service[nova-api]/ensure: change from stopped to running failed: Could not start Service[nova-api]: Execution of '/usr/bin/systemctl start     openstack-nova-api' returned 1: Job for openstack-nova-api.service failed because the control process exited with error code. See "systemctl status openstack-nova-api.service" and "journalctl -xe" for details.