Fix erp5_hal_json_style tests in Python 2

See merge request !1921
4 jobs for zope4py3 in 0 seconds
Status Job ID Name Coverage
  External
failed ERP5.CodingStyleTest-Zope4Py3

01:19:55

failed ERP5.CodingStyleTest-Zope4Py3-py2

01:24:26

failed ERP5.UnitTest-Zope4Py3

04:05:31

failed ERP5.UnitTest-Zope4Py3-Py2

01:54:43