pick up eventlet backdoor fix from oslo

eventlet backdoor had a misnamed variable in it (found by pyflakes).
The fix was already in oslo, sync to pick up this new fix.

Change-Id: Iede6443fd1a3f04d99607278d9afbb41bc9acdbf
Merge "pick up eventlet backdoor fix from oslo"
Merge remote-tracking branch 'citrix/master' into build-temp