[jdk17u-dev] RFR: 8307648: java/net/httpclient/ExpectContinueTest.java timed out

[Goetz Lindenmaier]

I would like to backport this along with the larger http redo in 17.
This fixes two minor issues to avoid misunderstandings in communication and thus timeouts. 

I had to do minor resolves because a later change was already backported.
Code now looks the same as in 21.

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Commit messages:
 - backport 04b0e785f6b9b4629b77bb19f2b072434be4951c

Changes: https://git.openjdk.org/jdk17u-dev/pull/3829/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=3829&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8307648
  Stats: 63 lines in 3 files changed: 54 ins; 0 del; 9 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/3829.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/3829/head:pull/3829

PR: https://git.openjdk.org/jdk17u-dev/pull/3829