Fail when "maxClients" > 0

[ulshv]

When client connects to socket.io it throws an error and fails.
"TypeError: io.sockets.clients is not a function"

It happens when maxClients in configuration > 0.

[ulshv]

Solved this. See socket.js file.
https://github.com/andyet/signalmaster/pull/77/files