Use sks-keyservers GPG server as primary
Use sks-keyservers GPG server as primary

This patch switches the order of keyservers since the
sks-keyservers server is more reliable than CentOS'
default.

Closes-Bug: 1723440
Change-Id: I9e18e518cf2baeb52f01531b96811cb1e4393cbc

openstack/openstack-ansible-pip_install,openstack/openstack-ansible-pip_install