https cannot support?

[huyinghuan]

I run the demo and everything is fine.
when I modify the server.js code:

var http = require('http');
var server = http.createServer(app);
var webRTC = require('webrtc.io').listen(server);
server.listen(8899);

to

var fs = require('fs');
var options = {
  key: fs.readFileSync(__dirname +'/key.pem','utf8'),
  cert: fs.readFileSync(__dirname +'/cert.pem','utf8')
};
var https = require('https');
var httpsServer = https.createServer(options, app);
var webRTC = require('webrtc.io').listen(httpsServer);
httpsServer.listen(8899)

when open the htpps://xxxhost:8899/ ,there cannot find other user ? anything I have forgotten? Thank you!