dms: set must_revalidate_http_cache for all pdf viewer skins

6 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-Master

00:42:02

failed ERP5.UnitTest-Master

01:34:18

failed ERP5.UnitTest-Zope2

01:44:51

passed SlapOS.Eggs.UnitTest-Master.Python2

00:14:18

passed SlapOS.Eggs.UnitTest-Master.Python3

00:15:07

passed Wendelin.UnitTest-Master

00:38:07