Update check_install_source checks for anaconda changes
    
    Since f33b50e, anaconda doesn't log "enabled repo:" any more. To
    ensure the repo actually is enabled we need to check some other
    lines. Good news is, we don't need the 'anaconda'|'' dodge any
    more, so we can drop that.
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>