Changed socket header in README instructions for CSRF.

[rdtscp]

Script says that websocket request headers are within io.sails.headers, however this would not apply for me, so i set io.socket.headers.

[mikermcneil]

Hey @acwilson96, thanks for looking into this. The reasoning here is that io.sails should be automatically merged as default config for every new socket, including the initial autoconnecting socket (io.socket). More background on that: https://next.sailsjs.com/documentation/reference/web-sockets/socket-client/io-sails