slapos_jio_ui_test: Ensure object is indexed before continue

Status Job ID Name Coverage
  External
passed SlapOS.Eggs.UnitTest-Master.Python2

00:20:57

failed SlapOS.Eggs.UnitTest-Master.Python3

00:21:38

passed SlapOS.Eggs.UnitTest-Master.Python2

00:21:11

passed SlapOS.Eggs.UnitTest-Master.Python3

00:19:00