ERP5Form: fix disabled fields not present in ZMI's "Order" tab

10 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
failed ERP5.CodingStyleTest-Master

01:09:26

failed ERP5.PerformanceTest-Master

00:29:24

failed ERP5.UnitTest-Master

02:01:40

failed ERP5.UnitTest-Zope2

04:06:34

passed SlapOS.Eggs.UnitTest-Master.Python2

00:19:46

passed SlapOS.Eggs.UnitTest-Master.Python3

00:21:54

passed Wendelin.UnitTest-Master

03:42:03

passed SlapOS.Eggs.UnitTest-Master.Python2

00:17:27

passed SlapOS.Eggs.UnitTest-Master.Python2

00:18:53

passed SlapOS.Eggs.UnitTest-Master.Python3

00:21:02