fixup! erp5_web_renderjs_ui: handle empty string value for float percent

5 jobs for for_testrunner_1
Status Job ID Name Coverage
  External
failed ERP5.UnitTest-Master

01:58:40

failed ERP5.UnitTest-Master.Medusa

passed SlapOS.Eggs.UnitTest-Master.Python2

00:26:19

passed SlapOS.Eggs.UnitTest-Master.Python3

00:29:09

failed ERP5.UnitTest-Master