Allow External Auth when Fallback Certificate is used

[erikflores7]

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Currently, you cannot configure both a Fallback Certificate and Authorization which means you lose Authorization if you do not have SNI available. In our specific use case, we cannot guarantee DNS records in our air-gapped, edge deployments and have to resort to using the IPs of our machines, at least initially. Since we use IPs, Chrome does not send the SNI and we have to resort to using the Fallback Certificate. This creates an issue since we can no longer authorize the requests that are coming in through our own auth service. We also cannot easily terminate TLS at the LB level since we do not have access to AWS or other LBs in these edge deployments. We would have to put something like Nginx Ingress Controller in front of Contour which we do not want to do. This is a requirement for deploying in edge deployments where there is a long process for obtaining DNS records/domains.