Don't mark down when known Trove licence present +license omitted

[hugovk]

According to https://packaging.python.org/guides/distributing-packages-using-setuptools/#license:

The license argument doesn't have to indicate the license under
which your package is being released, although you may optionally do
so if you want. If you're using a standard, well-known license, then
your main indication can and should be via the classifiers
argument. Classifiers exist for all major open-source licenses.

The "license" argument is more typically used to indicate differences
from well-known licenses, or to include your own, unique license. As a
general rule, it's a good idea to use a standard, well-known license,
both to avoid confusion and because some organizations avoid software
whose license is unapproved.

This was added in pypa/packaging.python.org#492 to "indicate that this argument is meant for deviations from the Trove classifier, not instead of it".

Actual result

If a project has a known Trove licence and the license classifier, it gets 10/10.

If the redundant license is removed, it's marked down to 9/10.

Expected result

Instead, pyroma should give 10/10 if there's a known Trove licence and no license argument. It should be marked down if it has both.

If the Trove licence is something like License :: Other/Proprietary License, it should be 10/10 when there is a license explaining what is being used, and marked down when license is missing.

[regebro]

Fixed