nixos/go2rtc: add support for v4l2 video sources

Capturing from /dev/video* requires being member of the video group.

Changed files
+4
nixos
modules
services
video
go2rtc
+4
nixos/modules/services/video/go2rtc/default.nix
···
serviceConfig = {
DynamicUser = true;
User = "go2rtc";
+
SupplementaryGroups = [
+
# for v4l2 devices
+
"video"
+
];
StateDirectory = "go2rtc";
ExecStart = "${cfg.package}/bin/go2rtc -config ${configFile}";
};