Updated openstack/openstack
Project: openstack/nova  051e496110ddb2d3c36baf43546969a84f05568b

Handle exception better in v2.1 attach_interface

Add more information when exception occurs in attach interface at Nova
v2.1 API layer.
The commit I7402cfc28d4ee7989c7eb054556df57918bbaeee has been merged
for v2.0 API, this patch does the same change for v2.1 API.

Partially implements blueprint v2-on-v3-api

Change-Id: I1b175501e6db48f27a894db2e66e09d31f8b50e2