setup.cfg is ignored in pyproject.toml already exists

Thanks for a cool tool, but I think I came across a bug!

I would like to keep the [bumpver] config info inside my setup.cfg file and not in pyproject.toml.

But if I do so, bumpver complains:

WARNING - Couldn't parse pyproject.toml: Missing version_pattern
ERROR   - Could not parse configuration. Perhaps try 'bumpver init'.

I believe that you check in sequence your supported config files and if pyproject.toml exists, you attempt to read from there and you never check the setup.cfg file...