named.conf template: update API for bind 9.11
    
    Use the new API for bind 9.11. Removed deprecated "serial_autoincrement"
    and updated the rest of configuration to conform to the new format.
    
    This only fixes new IPA installations. For existing installations,
    named.conf will be transformed when the new version of bind-dyndb-ldap
    is installed.
    
    https://fedorahosted.org/freeipa/ticket/6565
    
    Reviewed-By: Martin Basti <mbasti@redhat.com>