textproc/py-html2text: Update to 2020.1.16

This new version only supports Python >= 3.5.

Changelog: https://raw.githubusercontent.com/Alir3z4/html2text/2020.1.16/ChangeLog.rst

Update www/py-weboob to use Python >= 3.5 (avoid break bulk -a).

Reported by: Andrea Venturoli <ml@netfence.it>