Remove openstack AZ from templates

Remove openstack AZ from templates

When the availability_zone(AZ) is set, this returns the following
error. The cloud provider has recommended unsetting the value.

Error:
Build 'openstack' errored: Error creating volume:
Bad request with:
[POST https://volume.public.mtl1.vexxhost.net/v3/
f5ab9a59d6c649bd8ed4af258c4ba755/volumes],
error message: {"badRequest": {"code": 400, "message":
"Availability zone 'ca-ymq-2' is invalid."}}

Issue: https://jira.linuxfoundation.org/browse/IT-21300
Change-Id: Iaf65138629aad54534c0e50608b48d25338fbfdf
Signed-off-by: Anil Belur <abelur@linuxfoundation.org>