Fix timeout after 1 minute error on node >=v11.3 in websocket-relay

[alphacornutum]

In node 11.3, server.headersTimeout was introduced which defaults to 60 seconds. From that node version on, the websocket-relay.js streamServer would timeout after these 60 seconds, and close the incoming ffmpeg stream. This leads to a Error writing trailer of http://localhost:8081/supersecret: Broken pipe error in Ffmpeg.
Setting headersTimeout to 0 solves this.