incorrect policy check added to network-topo

[David Lyle]

https://review.openstack.org/414315 introduced an incorrect policy check to the network-topology panel. My comment there:

"I'm not sure how where this call is actually made and why it would be applicable to this particular panel, see https://github.com/openstack/horizon/blob/master/openstack_dashboard/dashboards/project/network_topology/views.py#L196
Which is where the data for the topology is gathered. When applying policy rules we can't infer or guess which one is applicable. I typically instrument the service server code to verify the policy calls made."

[David Lyle (david-lyle)]

The original patch was more widely problematic. This was resolved by reverting https://review.openstack.org/414315 see https://review.openstack.org/416331