No recent neutron deployment should ever have the port_binding extension
missing in its list.
It appears like this has been the case since this commit in Liberty:
61121c5f2af27e31092db7ac6947f796198410a8
It causing lots of confusion around when an admin_client should be used,
among other things, so lets remove this needless complexity.
Co-Authored-By: Augustina Ragwitz <auggy@cpan.org>
Change-Id: I5fa73fa0610b23ef231952b2035a284819186a7c
Related-Bug: 1608601