test: fix invalid argument order in test-http-expect-continue.js

`assert.strictEqual` expects arguments in the following order:

actual, expected[, message]

PR-URL: https://github.com/nodejs/node/pull/24138


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>