nixos/nebula: add reload support

Changed files
+1
nixos
modules
services
networking
+1
nixos/modules/services/networking/nebula.nix
···
Type = "notify";
Restart = "always";
ExecStart = "${netCfg.package}/bin/nebula -config ${configFile}";
+
ExecReload = "${pkgs.coreutils}/bin/kill -s HUP $MAINPID";
UMask = "0027";
CapabilityBoundingSet = capabilities;
AmbientCapabilities = capabilities;