handle negative cache rdatasets in _towire()
handle negative cache rdatasets in _towire()

each/bind9-collab,pecharmin/bind9,pecharmin/bind9,pecharmin/bind9,each/bind9-collab,pecharmin/bind9,each/bind9-collab,pecharmin/bind9,each/bind9-collab,each/bind9-collab,pecharmin/bind9,each/bind9-collab