[migration] fix handling of default value for boolean attributes We can't assert that the old value is 'True' or 'False', because False used to be stored as an empty string in pre-3.18 versions.

from os.path import join
assert __file__.endswith(join('scripts', 'script2.py')), __file__
assert '__main__' == __name__, __name__
assert ['-v'] == __args__, __args__