Replace leaked secret?

a45077a519087a60333aebabf36040d205fbd7a1 removed a leaked secret.

Whereas we could certainly use some of the methods recommended in https://help.github.com/en/articles/removing-sensitive-data-from-a-repository to remove it from the repo's history, I think the easiest way to fix this would be to simply replace the leaked secret for a new one in the upstream BlueGenes deployment.

Review commit a45077a519087a60333aebabf36040d205fbd7a1 and the linked GitHub guidance on removing sensitive data. Confirm which secret was leaked and how it is used by the upstream BlueGenes deployment, then replace it with a new value and verify that the old secret is no longer usable.

Written by the indexing model from the issue text.