test: fix incorrect indentation

Indentation is off in test-http-server-unconsume-consume.js.
The linter isn't complaining, but it probably should be.

PR-URL: https://github.com/nodejs/node/pull/11219


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>