[Checkins] [zopefoundation/Products.ZCatalog] e319a0: Replace __nonzero__ with __bool__ for py3

[Andreas Gabriel]

  Branch: refs/heads/notindexed_value_support
  Home:   https://github.com/zopefoundation/Products.ZCatalog
  Commit: e319a05d6044de502b17fa7ecbd4f0f8833de019
      https://github.com/zopefoundation/Products.ZCatalog/commit/e319a05d6044de502b17fa7ecbd4f0f8833de019
  Author: Andreas Gabriel <gabriel at hrz.uni-marburg.de>
  Date:   2019-05-24 (Fri, 24 May 2019)

  Changed paths:
    M src/Products/PluginIndexes/interfaces.py
    M src/Products/PluginIndexes/unindex.py
    M src/Products/ZCatalog/tests/test_zcatalog.py

  Log Message:
  -----------
  Replace __nonzero__  with __bool__ for py3