Comment 3 for bug 1430512

Note that the add/remove fixed_ips stuff was added to the neutronv2 (then quantum) API in Nova back in Grizzly via a simple bug report saying it wasn't implemented:

https://review.openstack.org/#/c/19627/

There aren't really any details in there, and the code is busted for the same reasons pointed out here, it's just that no one has ever seemed to care about it (or use it I guess). We can't just raise NotImplemented now though since that would be a backwards incompatible change to the multinic API extension.