The monkey patch for urllib.request._urlopener does nothing on Python 3.

(cherry picked from commit f1589378)
Status Job ID Name Coverage
  External
passed SlapOS.Buildout.UnitTest-Master.Python2

00:15:29

passed SlapOS.Buildout.UnitTest-Master.Python3

00:19:53

passed SlapOS.Buildout.UnitTest-Master.Python2

00:44:41

passed SlapOS.Buildout.UnitTest-Master.Python3

00:11:55