Drop undercloud-disable-nova.yaml
Drop undercloud-disable-nova.yaml

Nova is disabled on undercloud by default and there is
a new env file to enable it.

Depends-On: https://review.opendev.org/#/c/749876/
Closes-Bug: #1891242
Change-Id: Iaa5566131c5a5d00889f5cf1078f2b825f2b0325

openstack/tripleo-heat-templates,openstack/tripleo-heat-templates