test: refactor test-http-abort-before-end

This test was added over six years ago, and the behavior
seems to have changed since then. When the test was originally
written, common.mustCall() did not exist. The only assertion
in this test was not actually executing. Instead of an 'error'
event being emitted as expected, an 'abort' event was emitted.

PR-URL: https://github.com/nodejs/node/pull/18508


Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>