Fix ipv6 proxy url validation

[dosas]

Problem Statement

http_proxy_ipv6_url is accessed despite ipv6 is set to false on default.

pytest_fixtures/core/broker.py:55: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
/usr/lib/python3.11/contextlib.py:137: in __enter__
    return next(self.gen)
pytest_fixtures/core/broker.py:37: in _target_sat_imp
    _default_sat.enable_ipv6_http_proxy()
robottelo/hosts.py:1829: in enable_ipv6_http_proxy
    if not all([settings.server.is_ipv6, settings.server.http_proxy_ipv6_url]):
../../../.virtualenvs/robottelo/lib/python3.11/site-packages/dynaconf/utils/boxing.py:18: in evaluate
    value = f(dynabox, item, *args, **kwargs)
../../../.virtualenvs/robottelo/lib/python3.11/site-packages/dynaconf/utils/boxing.py:41: in __getattr__
    return super().__getattr__(n_item, *args, **kwargs)


E     dynaconf.vendor.box.exceptions.BoxKeyError: "'DynaBox' object has no attribute 'http_proxy_ipv6_url'"

Solution

using lazy evaluation the missing setting
will not be queried when ipv6 is disabled (default)

Related Issues

[omkarkhatavkar]

Can one of the admins verify this patch?