RFR: 7046003: Default value of Authenticator.getRequestingURL() is not specified

[kieran-farrell]

Clarificatiion of spec to outline that Authenticator.getRequestingURL() returns null in the event that the corresponding request does not specify a URL.

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Commit messages:
 - authenticator getRequestingURL spec update
 - update inetaddress javadoc

Changes: https://git.openjdk.org/jdk/pull/25097/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=25097&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-7046003
  Stats: 6 lines in 2 files changed: 3 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/25097.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25097/head:pull/25097

PR: https://git.openjdk.org/jdk/pull/25097