Steps to reproduce

1. Create a script in scripts/userscripts
2. Try to run it using pwb.py: python pwb.py my_script

Expected behavior
Until recently it was possible to run python pwb.py my_script if there was a my_script.py file in scripts/userscripts.

Current behavior
This is not possible now, running python pwb.py my_script speaks about misspelling. python pwb.py userscripts/my_script works, but it is a breaking change for my cron jobs. As it is a breaking change and there is no information in changelog / HISTORY.rst about it, so it might be a bug?

Configuration
Pywikibot master, Python 3.7.3+, Toolforge