Revert "Revert "Disable IPv6 in Net::LDAP. bugid:111222" bugid:111628"

This reverts commit 2fdab5305ec7791b97c706294f1428df62b14b71.
Revert "Revert "Add Sub::Uplevel to extlib for constant::override. bugid:111222" bugid:111628"

This reverts commit b199ea4ffcfa4ddc9f09845062290ed83392444f.