Only render NUT charts for actually available data and add a chart definition for `watt-ups` values while we're at it. Ref: https://forum.openwrt.org/t/x/156246 Signed-off-by: Jo-Philipp Wich <jo@mein.io>
Signed-off-by: Jo-Philipp Wich <jo@mein.io>
This conversion requires cgi-io >= version 17 and uhttpd version >= 2020-02-12 to function properly. Signed-off-by: Jo-Philipp Wich <jo@mein.io>