[FIX] kaltura: Test kaltura_kcwUIConf properly on admin page, and catch "SERVICE_FORBIDDEN" exceptions properly and present the message politely (and while trying to fix that the error just disappeared!)

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/11.x@46555 b456876b-0849-0410-b77d-98878d47e9d5