Error caused by es6 features in older version of node

[skorotkiewicz]

# dathttpd
/usr/lib/node_modules/dathttpd/lib/lets-encrypt.js:4
  return async (options, certs, cb) => {
               ^

[pfrazee]

Looks like I let some es6 creep into the project, which requires more recent versions of node.

It was easy to switch to purely es5, so I did. Try version 3.2.2