SSL (wss://) support for HTTPS pages
There is an error on the https pages in the browser:

```
Mixed Content: The page at 'xxxxxxxxxxx' was loaded over HTTPS, but attempted to connect to the insecure WebSocket endpoint 'ws://poolhost:8892/proxy'. This request has been blocked; this endpoint must be available over WSS.
```
There is two solutions:

1. Implement TLS: secure WebSocket bindings in proxy
https://github.com/crossbario/autobahn-python/tree/master/examples/twisted/websocket/echo_tls

```python
contextFactory = ssl.DefaultOpenSSLContextFactory('server.key', 'server.crt')
autobahn.twisted.websocket.listenWS(ws, contextFactory)
twisted.internet.reactor.listenSSL(8892, site, contextFactory)
```

2. Use reverse proxy to forward `wss://` requests to the local proxy port
https://stackoverflow.com/questions/12102110/nginx-to-reverse-proxy-websockets-and-enable-ssl-wss

Sample nginx configuration:

```nginx
location /proxy {
    proxy_pass ​http://localhost:8892;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "upgrade";
    proxy_read_timeout 86400;
}
```