erp5_ui_test: Fix typo

5 jobs for fix/test_fun in 0 seconds
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-Master

00:41:27

passed ERP5.PerformanceTest-Master

00:26:49

failed ERP5.UnitTest-Master

01:12:16

passed SlapOS.Eggs.UnitTest-Master.Python2

00:11:59

passed SlapOS.Eggs.UnitTest-Master.Python3

00:12:44