[Checkins] [zopefoundation/persistent] 91117f: Add change log entry.

[Michael Howitz]

  Branch: refs/heads/master
  Home:   https://github.com/zopefoundation/persistent
  Commit: 91117f66b38f4146d8523f29e21a792fa12cf3cb
      https://github.com/zopefoundation/persistent/commit/91117f66b38f4146d8523f29e21a792fa12cf3cb
  Author: Michael Howitz <mh at gocept.com>
  Date:   2019-04-24 (Wed, 24 Apr 2019)

  Changed paths:
    M CHANGES.rst

  Log Message:
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  Add change log entry.