Log Message:
ham/gr-osmosdr: Catch up with probably setuptools changes

This failed to build because PLIST has .pyc/.pyo, and now only .py is
installed.  I'm guessing that's due to changes in python tooling, and
that it's not wrong to not install compiled files.  Observed on NetBSD
10 amd64 with up-to-date pkgsrc HEAD.

Drop REPLACE_PYTHON because the build system does it already, so the
pkgsrc workaround is not needed.