Forcing the insecure protocol (and perserving the port number) is only
desired for localhost testing, in prod we need to use wss:// to avoid
mixed-content errors.
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
We can't do Noise-over-HTTP in Wasm/JS (because we don't have bidirectional
communication), but we should be able to do it over WebSockets. Reuses
derp WebSocket support that allows us to turn a WebSocket connection
into a net.Conn.
Updates #3157
Signed-off-by: Mihai Parparita <mihai@tailscale.com>
