redhat/packages: set allow_virtual to True
redhat/packages: set allow_virtual to True

RDO packaging provides virtual packages. Puppet 3 is setting
allow_virtual to False and in 4 it's set to True.
Force it to True to avoid issues when deploying RDO.

Change-Id: I54ade4cb4add005429840eb7d8970d736b1a0b22

openstack/puppet-openstack-integration,openstack/puppet-openstack-integration,openstack/puppet-openstack-integration