Update to 17.4.2

The upcoming update of news/sabnzbd to 3.0.0 needs an updated cherrypy.

This is not the newest release of cherrypy as that has dependencies that
aren't in ports yet, but this gets us from a 2016 release to a 2019 release

PR: 247597
Submitted by: James French <james@french.id.au>
Approved by: maintainer timeout