test: improve reliability of test-gc-http-client

test-gc-http-client is resource-intensive. It times out a lot on CI.
Move to sequential.

Approved for fast-tracking by:
Anna Henningsen <anna@addaleax.net>
Daniel Bevenius <daniel.bevenius@gmail.com>

PR-URL: https://github.com/nodejs/node/pull/23087
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
This commit is contained in:
Rich Trott 2018-09-25 13:29:54 -07:00 committed by Daniel Bevenius
parent 44d2d17fa6
commit 7d03ff188a