Fix a few python ports for new python extension format

PR: https://github.com/truenas/ports/pull/1019

devel/py-cffi, textproc/py-MarkupSafe, and textproc/py-pystemmer
were build dependencies when I was running a batch install of
the Samba port. They're currently broken in ports because of
python changes adding a new extension to .so files. This PR
contains the minimum changes to have Samba build successfully
in a pristine enviornment.