Fails with secure proxy

A HTTPS proxy with the likes of Caddy ([example](https://github.com/samhh/dotfiles/blob/6278f338476eeb51f2aae3eefb15f9a2d2b4c7cb/home/proxy/Caddyfile#L14)) will fail with live-server because `ws://` (as opposed to `wss://`) is hardcoded: https://github.com/lomirus/live-server/blob/v0.9.0/src/templates/websocket.js#L2 The page will load but the WebSocket will fail to connect.