DocImpact
This introduces an additional VNI so the hw_vif_model doc needs updating
to reflect this at:
https://docs.openstack.org/cli-reference/glance-property-keys.html
Change-Id: Ifc1636bff53cf74f889e1f4b632fa62c52d07b8e
Closes-Bug: 1638059
Signed-off-by: Thomas Stewart <thomas@stewarts.org.uk>