[jdk11u-dev] RFR: 8223714: HTTPSetAuthenticatorTest could be made more resilient

[luchenlin]

I backport this for parity with 11.0.20-oracle.

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Commit messages:
 - Backport 6b2e444aa1e9f6d2c6ade2aa1fb445805964ed85

Changes: https://git.openjdk.org/jdk11u-dev/pull/1931/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=1931&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8223714
  Stats: 150 lines in 1 file changed: 82 ins; 37 del; 31 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/1931.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/1931/head:pull/1931

PR: https://git.openjdk.org/jdk11u-dev/pull/1931