[jdk25u-dev] RFR: 8372147: ConnectionFlowControlTest should use HttpResponse.connectionLabel()

[Goetz Lindenmaier]

I backport this for parity with 25.0.3-oracle.

Trivial resolve.

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Commit messages:
 - backport 78b155b2b5745fc88c13586f93b632f61e038a94

Changes: https://git.openjdk.org/jdk25u-dev/pull/328/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk25u-dev&pr=328&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8372147
  Stats: 5 lines in 1 file changed: 0 ins; 1 del; 4 mod
  Patch: https://git.openjdk.org/jdk25u-dev/pull/328.diff
  Fetch: git fetch https://git.openjdk.org/jdk25u-dev.git pull/328/head:pull/328

PR: https://git.openjdk.org/jdk25u-dev/pull/328