Update PowerDNS configuration keys
    
    Tumbleweed received version 4.9.0, which removed deprecated
    options, making this patch needed for Tumbleweed based servers.
    Leap ships 4.7.3, where the old options are still valid but
    deprecated, making it sensible to also adapt them there for
    future proofing.
    
    https://doc.powerdns.com/authoritative/upgrading.html#to-4-9-0
    
    Signed-off-by: Georg Pfuetzenreuter <mail@georg-pfuetzenreuter.net>