RFR: 8327989: java/net/httpclient/ManyRequest.java should not use "localhost" in URIs

[Daniel Fuchs]

Please find here a trivial test fix that remove usage of "localhost" from ManyRequest.java.
Use of "localhost" in test URIs is problematic as it leaves the test open to random failure when running on machines that have custom mappings for "localhost". The fix is to use the IP literal of the loopback address instead.

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Commit messages:
 - 8327989

Changes: https://git.openjdk.org/jdk/pull/18239/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18239&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8327989
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/18239.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18239/head:pull/18239

PR: https://git.openjdk.org/jdk/pull/18239