Comment 2 for bug 1745168

Gorka found that a native thread within a greenthread is logging. Shouldn't be doing that.

Jan 24 15:04:16.031978 ubuntu-xenial-citycloud-sto2-0002119447 cinder-backup[11788]: Traceback (most recent call last):
9:48 AM Jan 24 15:04:16.032126 ubuntu-xenial-citycloud-sto2-0002119447 cinder-backup[11788]: File "/usr/local/lib/python2.7/dist-packages/eventlet/hubs/hub.py", line 457, in fire_timers
9:48 AM Jan 24 15:04:16.032267 ubuntu-xenial-citycloud-sto2-0002119447 cinder-backup[11788]: timer()
9:48 AM Jan 24 15:04:16.032404 ubuntu-xenial-citycloud-sto2-0002119447 cinder-backup[11788]: File "/usr/local/lib/python2.7/dist-packages/eventlet/hubs/timer.py", line 58, in __call__
9:48 AM Jan 24 15:04:16.032559 ubuntu-xenial-citycloud-sto2-0002119447 cinder-backup[11788]: cb(*args, **kw)
9:48 AM Jan 24 15:04:16.032703 ubuntu-xenial-citycloud-sto2-0002119447 cinder-backup[11788]: File "/usr/local/lib/python2.7/dist-packages/eventlet/semaphore.py", line 145, in _do_acquire
9:48 AM Jan 24 15:04:16.032840 ubuntu-xenial-citycloud-sto2-0002119447 cinder-backup[11788]: waiter.switch()
9:48 AM Jan 24 15:04:16.032990 ubuntu-xenial-citycloud-sto2-0002119447 cinder-backup[11788]: error: cannot switch to a different thread

This change merged the same day: https://github.com/openstack/cinder/commit/1a569e15c35d772a8ca236d75cd1840a415983d3

Gorka is investigating.