To Reproduce Steps to reproduce the behavior:

1. Provision a single stack ipv6 OCP env
2. Deploy RHOSO with Horizon enabled
3. Observe the error

Expected behavior

• IP address should be correctly determined even if no IPV4 address is available

Bug impact

• Prevents users in single stack IPv6 environments from using Horizon.

Known workaround

• None

Additional context

Error observed:

ALLOWED_HOSTS = [get_pod_ip(), "horizon-openstack.apps.lab._redacted_"]
File "/usr/lib/python3.9/site-packages/openstack_dashboard/local/local_settings.py", line 72, in get_pod_ip
s.connect(hostport)
OSError: [Errno 101] Network is unreachable 

Issue raised on Github:
https://github.com/openstack-k8s-operators/horizon-operator/issues/478

Proposed PR:
https://github.com/openstack-k8s-operators/horizon-operator/pull/496