fixes #8261 - use Default Organization for certificate org

I don't think that should be used there at all. If anything, it should use -- https://github.com/Katello/katello-installer/blob/master/config/answers.katello-installer.yaml#L10 for the capsule registration example. The org specified in the CA should not necessarily have anything to do with any particular internal Foreman/Katello organization and more so reflect the "broader" organization or application itself.