test: don't check the # of chunks in test-http-1.0

As it can happen that the HTTP response is received in more than
one TCP chunk.

PR-URL: https://github.com/nodejs/node/pull/3961


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Fedor Indutny <fedor@indutny.com>
Reviewed-By: Minwoo Jung <jmwsoft@gmail.com>