Draft: fix/clean
we got
TypeError: '<' not supported between instances of 'NoneType' and 'NoneType'
need also clean up between erp5_calendar and erp5_payroll_l10n_fr
/cc @tsoulard
we got
TypeError: '<' not supported between instances of 'NoneType' and 'NoneType'
need also clean up between erp5_calendar and erp5_payroll_l10n_fr
/cc @tsoulard