[nova] Gerrit breach and commit audit

Hello Everyone,

As per the announcement of the Gerrit breach [1], I have audited all repos under Nova for 1. Suspicious commit 2. Core group list

and everything is fine.

- https://etherpad.opendev.org/p/nova-gerrit-breach-audit

[1] http://lists.opendev.org/pipermail/service-announce/2020-October/000011.html