previously, a managed-keys zone was created for every view
regardless of whether rfc5011 was in use; when it was not in
use, the zone would be left empty. this made for some confusing
log messages.
we now only set up the managed-keys zone if dnssec-validation is
set to the default value of "auto".
certain system test servers have had their dnssec-validation settings
changed to auto because the tests depended on the existence of the
zone.