Monkey patch original current_thread _active
Monkey patch original current_thread _active

Monkey patch the original current_thread to use the up-to-date _active
global variable. This solution is based on that documented at:
https://github.com/eventlet/eventlet/issues/592

Change-Id: I0e8f80bb2e7acfb00e5ff47e0aa983afb7ee6e38
Closes-Bug: #1863021

openstack/murano-agent,openstack/murano-agent,openstack/murano-agent,openstack/murano-agent