app: listen to `error` on next tick

okay this is a really trivial issue. i'd like a way to "filter" errors from printing to `console.error`. right now, a bunch of `ECONNRESET` errors are being printed to the console because i have a client that frequently `.destroy()`s request. in other words, there are always those errors we don't care about because we can't do anything about.

one way we could do this is to create some sort of `.filterError` method, but more API? no thanks.

my solution is to set the `error` listener on next tick so i can set `.onerror` myself. of course i could do `app.removeListeners('error'); this.on('error', mylistener)`, but meh.