Fix handshake never starting when using options.stream

[u9g]

Problem

Creating a client with a custom stream (options.stream) hangs forever without sending the handshake:

const socket = net.connect(PORT, host, () => {
  const client = mc.createClient({ username: 'x', version: '1.21.8', stream: socket })
  // never emits 'login', no bytes ever written
})

For offline auth, createClient calls options.connect(client) before onReady() runs. The stream branch in tcp_dns.js emits 'connect' synchronously inside that call, so setProtocol (which subscribes in onReady() and sends set_protocol on 'connect') never sees the event. The plain-socket path doesn't hit this because net.connect completes asynchronously.

It reproduces whenever the provided stream doesn't emit its own 'connect' later — e.g. an already-connected socket, or any generic Duplex (I hit this tunneling the protocol bytes over a WebSocket).

Fix

Defer the emit one tick so listeners registered after options.connect() returns still see it.

Added a regression test in serverTest.js — it times out on master and passes with the fix, across all supported versions.