[Checkins] [zopefoundation/RestrictedPython] 33c1e9: Remove no longer existing extra.

[Michael Howitz]

  Branch: refs/heads/master
  Home:   https://github.com/zopefoundation/RestrictedPython
  Commit: 33c1e950729c0971db3e956e854f38c6dc5e0cab
      https://github.com/zopefoundation/RestrictedPython/commit/33c1e950729c0971db3e956e854f38c6dc5e0cab
  Author: Michael Howitz <mh at gocept.com>
  Date:   2020-03-31 (Tue, 31 Mar 2020)

  Changed paths:
    M tox.ini

  Log Message:
  -----------
  Remove no longer existing extra.