erp5_web_renderjs_ui: remove unsafe-eval CSP

It was required by Handlebars
4 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
failed ERP5.CodingStyleTest-Master

01:23:24

passed ERP5.PerformanceTest-Master

00:32:35

failed ERP5.UnitTest-Master

01:53:55

passed SlapOS.Eggs.UnitTest-Master.Python2

00:34:15