remove an XXX

lib/check-signature.js

@@ -2,8 +2,6 @@
 /* global process */
 const Nacl = require('tweetnacl/nacl-fast');
 
-// XXX npm "os" and "child_process"
-
 // TODO if this process is using too much CPU, we can use "cluster" to add load balancing to this code
 //console.log('New child process', process.pid);
 process.on('message', function (data) {