fix error handling for the restful API

node_modules/vfs-http-adapter/restful.js

@@ -12,6 +12,7 @@ module.exports = function setup(mount, vfs, mountOptions) {
     var errorHandler = mountOptions.errorHandler || function (req, res, err, code) {
         console.error(err.stack || err);
         if (code) res.statusCode = code;
+        else if (typeof err.code == "number") res.statusCode = err.code;
         else if (err.code === "EBADREQUEST") res.statusCode = 400;
         else if (err.code === "EACCES") res.statusCode = 403;
         else if (err.code === "ENOENT") res.statusCode = 404;