Update prerelease note needle for F40
    
    The existing needle matches on bits of the keyboard layout
    selector under the note and the Help button next to it, for some
    reason (I don't recall why). The Help button is gone because we
    killed installer help, and the keyboard layout indicator is not
    always shown any more, there's no reason to match on it here
    that I can recall.
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>