Changes regarding redirect handling by the service worker

Hi everyone

For security reasons we have updated the service worker to no longer allow redirects as a response to http_request (see specification).

If you run into issues because your canister needs to redirect, please set status code 200 and the upgrade flag on the response to http_request and then redirect in the call to http_request_update. This will however increase latency of the redirect by approximately 2 seconds.

We are working on a new certification scheme that will again allow redirects using query calls.

Feel free to ask questions if anything is unclear.