fixup! fixup! Zope2: use func_code if __code__ is missing, that is the case for Script (Python).

21f85a6f
added zope2 compatibility, but 21f85a6f (comment 180420) noted
the given assumption isn't true, which is why fixup commit 7a2c616e was
added. But 21f85a6f (comment 184548) noted
that 7a2c616e missed one case,
which is why this fixup commit is added. Now everything should be ok.