Use ipaldap exceptions rather than ldap error codes in LDAP updater
The code in ipaldap got changed with df4ed77 but ldapupdate was never updated.
Closes: https://pagure.io/freeipa/issue/7610
Reviewed-By: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>