Bintray service is closing

[abitmore]

Build Error Description

As of writing our CI process relies on Bintray to get source code of boost library.
However, according to the link https://jfrog.com/blog/into-the-sunset-bintray-jcenter-gocenter-and-chartcenter/ , Bintray is closing, so this CI job failed: https://github.com/bitshares/bitshares-core/pull/2426/checks?check_run_id=2441659025

We need to get around it.

Build Environment
Details about the build environment, including the relevant required libraries. Much of this information can be found in the CMakeFiles/CMakeOutput.log.

• Host OS: MinGW
• Host Physical RAM -
• Source Branch/Tag: release
• OpenSSL Version: -
• Boost Version: -
• C++ Compiler: -

CORE TEAM TASK LIST

• Evaluate Build Error
• Provide build guidance
• Create Bug Report

[abitmore]

According to boostorg/boost#502 (comment), the new download link is here: https://boostorg.jfrog.io/artifactory/main/release/

[abitmore]

Fixed by #2426.