Message 264229 - Python tracker

With changeset 0d74d4937ab9, test_pwd fails on android API level 21 at test_values with:
  Traceback (most recent call last):
    File "/sdcard/org.bitbucket.pyona/lib/python3.6/test/test_pwd.py", line 27, in test_values
      self.assertIsInstance(e.pw_passwd, str)
  AssertionError: None is not an instance of <class 'str'>

On android API 21 HAVE_STRUCT_PASSWD_PW_PASSWD is defined but p->pw_passwd is set to NULL.