laserproxy: add nix build

Change-Id: If93f4ba69afa028fed9098663a523f46d6134f7c
diff --git a/default.nix b/default.nix
index c284030..cc761d4 100644
--- a/default.nix
+++ b/default.nix
@@ -31,6 +31,7 @@
 
   bgpwtf = readTree config ./bgpwtf;
   cluster = readTree config ./cluster;
+  hswaw = readTree config ./hswaw;
   ops = readTree config ./ops;
 
   pkgs = nixpkgs;