http: fix assert on data/end after socket error

This change is a backport of 1a3ca822
from io.js.

Original commit message:

  Read all pending data out of the socket on `error` event and ensure that
  no `data`/`end` handlers will be invoked on `socket.destroy()`.
  Otherwise following assertion happens:

      AssertionError: null == true
          at TLSSocket.socketOnData (_http_client.js:308:3)
          at TLSSocket.emit (events.js:107:17)
          at TLSSocket.Readable.read (_stream_readable.js:373:10)
          at TLSSocket.socketCloseListener (_http_client.js:229:10)
          at TLSSocket.emit (events.js:129:20)
          at TCP.close (net.js:476:12)

  Fix: https://github.com/joyent/node/issues/9348
  PR-URL: https://github.com/iojs/io.js/pull/1103


Reviewed-By: Rod Vagg <rod@vagg.org>
Reviewed-By: Nicu Micleușanu <micnic90@gmail.com>

Fixes #9348.

Reviewed-By: Julien Gilli <julien.gilli@joyent.com>
PR-URL: https://github.com/joyent/node/pull/14087