[serverctl] fix default value for db-init config-level Otherwise cubicweb-ctl db-init --automatic complains that "--automatic and --config-level should not be used together" when they weren't. Closes #3984336

from os.path import join
assert __file__.endswith(join('scripts', 'script1.py')), __file__
assert '__main__' == __name__, __name__
assert [] == __args__, __args__