Avoid setup_requires offline installation issues 
Avoid setup_requires offline installation issues 

Currently, it's not possible to install jsonschema offline, as pip cannot found setup_requires dependencies.
See https://www.scivision.dev/setuptools-pyproject-toml-offline/ and https://stackoverflow.com/questions/27307082/install-package-which-has-setup-requires-from-local-source-distributions.
Simply removing the option from setup.cfg do the trick.
python-jsonschema/jsonschema,Julian/jsonschema,Julian/jsonschema