[Checkins] [zopefoundation/Zope] f9604f: - prevent ImportErrors under Python 2 with ZServer

[Jens Vagelpohl]

  Branch: refs/heads/4.x
  Home:   https://github.com/zopefoundation/Zope
  Commit: f9604fe78565fd0ab4dd88995879299090be618c
      https://github.com/zopefoundation/Zope/commit/f9604fe78565fd0ab4dd88995879299090be618c
  Author: Jens Vagelpohl <jens at netz.ooo>
  Date:   2020-04-19 (Sun, 19 Apr 2020)

  Changed paths:
    M src/App/DavLockManager.py
    M src/OFS/Lockable.py
    M src/OFS/bbb.py

  Log Message:
  -----------
  - prevent ImportErrors under Python 2 with ZServer