Configures haproxy to serve novnc_proxy

This patch configures haproxy to serve novnc_proxy which currently
listens on 0.0.0.0. So before this patch goes in novnc needs to be
listening on local-ipv4 like the rest of the services. The following
patch does that in image-elements.

https://review.openstack.org/#/c/125326/

Change-Id: I0c6a3d6a8fd10da71abbf568633b28bdb5e56aa2
Merge "Configures haproxy to serve novnc_proxy"