The 'loaded' property on TLS creds and secret objects was marked as
deprecated in 6.0.0. In 7.1.0 the deprecation info was moved into
the 'removed-features.rst' file, but the property was not actually
removed, just made read-only. This was a highly unusual practice,
so finish the long overdue removal job.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>