DNSSEC: remove keys purged by OpenDNSSEC from master HSM from LDAP
Key purging has to be only only after key metadata purging so
ipa-dnskeysyncd on replices does not fail while dereferencing
non-existing keys.
https://fedorahosted.org/freeipa/ticket/5334
Reviewed-By: Martin Basti <mbasti@redhat.com>