Update the URLs in two places in the test_upgrade script.
* boost-program-options dependency points to
    archives.fedoraproject.org
* gpgkey for the MariaDB rpm repository points to
    archive.mariadb.org/PublicKey

This ensures that the upgrade testing run in .gitlab-ci.yml continues to
function and refers to the correct GPG key.

All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer Amazon Web
Services.