py3: avoid None >= None comparison.

3 jobs for zope4py3 in 0 seconds
Status Job ID Name Coverage
  External
failed ERP5.UnitTest-Zope4Py3-jerome

01:10:32

failed ERP5.UnitTest-Zope4Py3-jerome

01:12:59

failed ERP5.UnitTest-Zope4Py3-jerome

01:02:26