Revert "Add beta site to wikisource"
Revert "Add beta site to wikisource"

Tests are failing:
https://integration.wikimedia.org/ci/job/pywikibot-core-tox-fasttest-py27-docker/682/console

This reverts commit c0dfc3675bec60e8ac47e62d7386ab3060712607.

Change-Id: I444c0a0974cdfa810bf422dda25cdaff28363cd7

wikimedia/pywikibot-core,wikimedia/pywikibot-core,PersianWikipedia/pywikibot-core