fixes #8261 - use Default Organization for certificate org

I still *this* value should be something that is *not* an organization within the application itself. Since this is the certificate for the entire application a better default would be 'Katello' or 'Foreman' or for branding 'Satellite' or force users to set this value. For this, https://github.com/Katello/katello-installer/pull/136/files#diff-d9b1058a236a3d65bd0c4fbc0b60f640R53, I think you should set it to the initial organization param.