[Checkins] [zopefoundation/RestrictedPython] ad32fb: Fix breaking Python 3.9.0a5.

[Michael Howitz]

  Branch: refs/heads/fix-193
  Home:   https://github.com/zopefoundation/RestrictedPython
  Commit: ad32fb15217de1a5809a6307f5f14859559ad7fb
      https://github.com/zopefoundation/RestrictedPython/commit/ad32fb15217de1a5809a6307f5f14859559ad7fb
  Author: Michael Howitz <mh at gocept.com>
  Date:   2020-03-31 (Tue, 31 Mar 2020)

  Changed paths:
    M docs/CHANGES.rst
    M setup.py
    M src/RestrictedPython/transformer.py
    M tests/transformer/test_subscript.py

  Log Message:
  -----------
  Fix breaking Python 3.9.0a5.

Fixes #193.