CONSOLE ERROR: line 387: Mixed Content: The page at 'https://web-platform.test:8444/mixed-content/websocket-request/http-csp/same-host-ws/top-level/keep-scheme-redirect/blockable/ws-downgrade-blocks.https.html' was loaded over HTTPS, but attempted to connect to the insecure WebSocket endpoint 'ws://web-platform.test:9001/stash_responder?redirection=keep-scheme-redirect&action=purge&key=8f027593-3633-44d8-afb4-6ce7c0e5d0d9&path=%2Fmixed-content&content_type=application/json'. This request has been blocked; this endpoint must be available over WSS.
