In v3, we need to be able to use some variables from zuul/web.pp in the
vhost template, but the vhost is created in ::zuul because of how v2
worked.
Split the config, and split where we're defining it so that in the next
patch we can make use of variables from zuul/web.pp.
Change-Id: I3e1c72bb773be050854f5563d09f6c19af8bc6dc
Depends-On: https://review.openstack.org/557085
fa66845b5b