Replace neutron.common.rpc.create_connection calls
Replace neutron.common.rpc.create_connection calls

The code is still relying on neutron.common.rpc.create_connection,
which has recently been removed [1]. Replacing that with a call
to the Connection constructor, which has the same effect.

[1] https://review.openstack.org/560130

Change-Id: I7d349f7389ba88c2331cdfa9a9c6c4cbc2fab75b
Closes-Bug: 1777919

openstack/networking-vsphere,openstack/networking-vsphere,stackforge/networking-vsphere,stackforge/networking-vsphere