The DNS ordering and OVN DHCP documents were out-of-date
and using the old neutronclient, updated.
Noticed while fixing an openstackclient bug related to
dns_nameservers ordering.
TrivialFix
Related-bug: #2053201
Change-Id: Iab15750a4adc8dc78d839f0a1b952f9d87bdab8a