workstation: Don't install icedtea-web by default
    
    icedtea-web clutters the application view with two launchers for config
    dialogs which are not really apps as we define the term.
    
    It used to be excluded previously but accidentally slipped back in with
    the live-desktop -> live-workstation kickstart renames; this commit
    takes it out again.
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1131248