Updated openstack/openstack
Project: openstack/oslo-incubator  29f744159c45f10f51441496f071ddda1b9fa71c

Use file locks by default again

Backport of f1688a70f28a15cb864651f534344faab92c0d1f from
oslo.concurrency.

Closes-Bug: 1327946

Change-Id: Ia64eee85901f5ff2717f5ea24ecb039151a5ffb9