The domain lesswatts.org which is listed as (secondary) homepage for sys-power/powertop-1.13 sys-power/powertop-9999 doesn't exist anymore. It should be replaced/dropped in favor of https://01.org/powertop/
updated on 9999 but 1.13 isn't available on the new page so there is no point in upgrading. it will be removed once 2.x is stable anyway. thanks for the report