Revert "TR: Switch Cinder to use oslo.concurrency"

This reverts commit 8a1f2ecafceaa8ce81b670d7f06a23da575b4403.
The revert is no longer needed, we've added the appropriate
config variable into the cinder element.
See Idcabf808d5f7255d0cc382b7857a4c13b9b7a2dc

Change-Id: Idde47b728f9b472cd48420f9e212cdc8a6a1c8bf
Merge "Revert "TR: Switch Cinder to use oslo.concurrency""