Fix for ticket 50059: If an object is nsds5replica, it must be cn=replica
    
    Bug Description:
    
    We should enforce that if an object is of type nsds5replica, it must be named cn=replica.
    This has caused some confusion where people have misconfigured their system by trying alternate names.
    
    Fix Description:
    
    Check that rdn of replica dn is exactly REPLICA_RDN
    
    https://pagure.io/389-ds-base/issue/50059
    
    Author: German Parente <gparente@redhat.com>
    
    Review by: ???