The Neutron API with WSGI module, and specifically when using ML2/OVN,
was importing some system libraries before patching them. That was
leading to a recursion error, as reported in the related LP bug.
By calling ``eventlet_utils.monkey_patch()`` at the very beginning
of the WSGI entry point [1], this issue is fixed.
[1] WSGI entry point:
$ cat /etc/neutron/neutron-api-uwsgi.ini
...
module = neutron.wsgi.api:application
Closes-Bug: #2075147
Change-Id: If2aa37b2a510a85172da833ca20564810817d246
76f343c586