Fixes filtering in delete and update in PowerDNS
Fixes filtering in delete and update in PowerDNS

Change-Id: I9bcf798604de6ff91919eff2cd7e3f2c61180f08
Closes-Bug: #1285227

kiall/designate-py3,ionrock/designate,richm/designate,openstack/designate,tonyli71/designate,cneill/designate,ramsateesh/designate,melodous/designate,cneill/designate-testing,cneill/designate,kiall/designate-py3,richm/designate,cneill/designate,cneill/designate,cneill/designate,kiall/designate-py3,ramsateesh/designate,ionrock/designate,NeCTAR-RC/designate,grahamhayes/designate,tonyli71/designate,tonyli71/designate,NeCTAR-RC/designate,openstack/designate,muraliselva10/designate,kiall/designate-py3,cneill/designate-testing,melodous/designate,muraliselva10/designate,grahamhayes/designate,openstack/designate,grahamhayes/designate,melodous/designate,kiall/designate-py3,muraliselva10/designate,cneill/designate-testing,ramsateesh/designate,ionrock/designate,melodous/designate