GPO: Add option ad_gpo_ignore_unreadable
Add option to ignore group policy containers in AD
with unreadable or missing attributes. This is
for the case when server contains GPOs that
have very strict permissions on their attributes
in AD but are unrelated to access control.
Rather then using this option it is better to
change the permissions on the AD objects but
that may not be always possible (company policy,
not access to server etc.).
Reviewed-by: Jakub Hrozek <email@example.com>
(cherry picked from commit 2f27dd9f05c2d3ed1c190ba387bc97738988efb0)