Fix docs failures caused by latest eventlet
Fix docs failures caused by latest eventlet

Closes-bug: #1674687

Change-Id: I9c44f84b1eb4f25a2c87612b444d22f12e6f22ce

j-griffith/cinder,mahak/cinder,mahak/cinder,eharney/cinder,openstack/cinder,openstack/cinder,eharney/cinder,Datera/cinder,j-griffith/cinder,phenoxim/cinder,phenoxim/cinder,Datera/cinder