Updated openstack/openstack
Project: openstack/nova  d924500e413b66d49642ab88f4abc6fc7b24d2a5

Logging detail when attach interface failed

When attach interface failed, there isn't any detail for
error info. Change the log level to exception to get more detail.

Change-Id: If531c32357dbb002a3e92e4ca559eeb7f6ab6d2d
Closes-Bug: #1373761