Pipelines with GAE gitHttpsUsername/gitHttpsPassword fail with 'Not authorized' Exception

Issue

Pipelines with GAE gitHttpsUsername/gitHttpsPassword are seen to fail with a Not authorized exception. 

Cause

This is owing to GitHub starting to enforce 2FA and that doesn't work for automated environments. The problem with the library failing on using a password is a known issue, related to 2FA: https://github.com/eclipse/dirigible/issues/194