change for rooms to work

[tommytee]

edit needed for rooms to work.
I am using with updated socket.io-p2p https://github.com/socketio/socket.io-p2p/pull/36

[rogual]

@tommytee You've moved your master branch so this PR now has extra stuff in it. (The first commit works though — thank you!)

[tommytee]

Thanks. I removed that commit from the PR.

[runemadsen]

+1