erp5_wendelin_data_lake_ui: hide register panel entry when user is logged in

See merge request !106
4 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
failed SlapOS-Master.UnitTest-Master

03:44:32

failed SlapOS-Master.UnitTest-Master

03:06:53

failed SlapOS-Master.UnitTest-Master

00:16:11

failed SlapOS-Master.UnitTest-Master

03:27:43