Updated openstack/openstack
Project: openstack/glance  b4b90395e31260990b0ee203ce0f685b258d952e

rename oslo.concurrency to oslo_concurrency

oslo.concurrency-0.3.0 has moved its path to oslo_concurrency,
the old path oslo.concurrency can still work but is deprecated now.

Change-Id: Idbf6ea10ddf6fdab9695c6dfb132bd720394ffdf
Closes-Bug: #1398656