RFR: 8317357: Update links in building.md to use https rather than http

Thu Nov 16 17:15:41 UTC 2023

>From the bug report: Building.md file contains a number of HTTP links that would need to be converted to HTTPS in order for clicking on the links on the OpenJDK web site at https://openjdk.org/groups/build/doc/building.html to work. 

It is also best practice nowadays to always prefer https in links; most http requests are upgraded to https anyway.

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Commit messages:
 - 8317357: Update links in building.md to use https rather than http

Changes: https://git.openjdk.org/jdk/pull/16695/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=16695&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8317357
  Stats: 36 lines in 2 files changed: 0 ins; 0 del; 36 mod
  Patch: https://git.openjdk.org/jdk/pull/16695.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16695/head:pull/16695

PR: https://git.openjdk.org/jdk/pull/16695