[Checkins] [zopefoundation/DocumentTemplate] dcd491: Restore `check-only` flag for `isort`

[Jürgen Gmach]

  Branch: refs/heads/fix-flake8
  Home:   https://github.com/zopefoundation/DocumentTemplate
  Commit: dcd491402c571303d5c906cec7d23e6361818963
      https://github.com/zopefoundation/DocumentTemplate/commit/dcd491402c571303d5c906cec7d23e6361818963
  Author: Jürgen Gmach <juergen.gmach at googlemail.com>
  Date:   2020-10-08 (Thu, 08 Oct 2020)

  Changed paths:
    M tox.ini

  Log Message:
  -----------
  Restore `check-only` flag for `isort`

modified:   tox.ini