replication: check remote ds version before editing attributes
    
    When the remote server has an old DS version, update of the
    replication attributes nsds5ReplicaReleaseTimeout nsds5ReplicaBackoffMax
    and nsDS5ReplicaBindDnGroupCheckInterval fails even if the remote
    schema has been updated.
    
    Check first the remote server version and update the attributes only if
    the version is high enough.
    A previous fix was already performing this check (commit 02f4a7a),
    but not in all the cases. This fix also handles when the remote server
    already has a cn=replica entry (for instance because it has already
    established replication with another host).
    
    Fixes https://pagure.io/freeipa/issue/7796
    
    Reviewed-By: Christian Heimes <cheimes@redhat.com>