Set MASTER_SITE_SUBDIR again.

The port had been broken since October 2014 when r371113 stopped setting the
MASTER_SITE_SUBDIR. Like devel/py-cycler, the PyPI location is a bit unusual,
with the tarball name being "blogofile-XXX.tar.gz" (lowercase 'b') and the
directory being called "Blogofile", with capital 'B'.