NAT-PMP will always timeout

[SilentBot1]

Hey,

Currently the NAT-PMP implementation of this library will never succeed when performing any actions due to a missing property when pushing the request to the _queue, which causes onMessage to always return early.

The op property is missing from the following _queue push:

nat-api/lib/pmp/index.js

Line 178 in 16fd1e4

this._queue.push({ buf: buf, cb: cb })

Which is causing this check:

nat-api/lib/pmp/index.js

Line 260 in 16fd1e4

if (parsed.op - SERVER_DELTA !== req.op) {

To always fail, as the parsed.op - SERVER_DELTA will never equal undefined.

From local testing, I can confirm this does add the mapping via NAT-PMP, but will never fully handle the response, causing the request to always timeout, falling back to NAT-UPNP, which may not be supported in all environments.