This reverts commit e3de45359f.
We need to improve out strategy by adding a cache breaker with this change ... some assets on CDNs and clients may have incorrect CORS headers which can cause stuff to break.
- Define the CSP based on the requested domain / scheme (respecting force_https)
- Update EnforceHostname middleware to allow secondary domains, add specs
- Add URL scheme to anon cache key so that CSP headers are cached correctly
