It was recently decided to uncap eventlet:
http://lists.openstack.org/pipermail/openstack-dev/2018-April/129096.html
So eventlet is now capped at 0.20 not by global requirements,
it is capped in upper-constraints, because currently not every
openstack project is able to work with a newer eventlet version,
mostly because of the caps in projects requirements.txt.
According to global-requirements, last allowed version of
eventlet is 0.22.1:
https://git.openstack.org/cgit/openstack/requirements/tree/global-requirements.txt
In an effort to support both eventlet<0.22 and eventlet>=0.22,
change the code to try and determine the correct number of
arguments to use in the call to initialize the parent class.
Change-Id: Ibe3dc8af6cf9f8bb4f8eababb7f4276e4db3f1f9
Closes-bug: #1777640
d1efeeb433