Some devices throw an hidpp20::Error InvalidFeatureIndex when Root
GetFeature is called with some features (e.g. 0x1b04) as the parameter.
Since Root is a required feature in the HID++ 2.0 protocol, this error
can safely be ignored and treated as an UnsupportedFeature.
Fixes bug in #20 where the Logitech PRO headset would not work.
pixl
0b87d3c664