Review request: python-jenkins-job-builder - unretire and update to 4.0.0

[Christoph Erhardt]

Hi all,

I'm willing to revive python-jenkins-job-builder by updating it to the latest 
release 4.0.0 and backporting an upstream patch.
I already have a working Copr build: https://copr.fedorainfracloud.org/coprs/
sicherha/python-jenkins-job-builder/packages/

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2084340

Best,
Christoph