erp5_content_translation: fix Translation form for new UI.

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

00:33:34

passed ERP5.PerformanceTest-Master

00:26:23

failed ERP5.UnitTest-Master

01:18:31

failed ERP5.UnitTest-Master.Medusa

01:12:56

passed SlapOS.Eggs.UnitTest-Master.Python2

00:12:15

passed SlapOS.Eggs.UnitTest-Master.Python3

00:14:00