Specify a single protcol as "protocol1" instead of, previously, "protocol1,"

Hello I've been trying to implement WebSocket client side which needed to send string "text-stream" as sub-protocol in handshake key. But WebSocketWriter send "text-stream," So I suggest to add in the method sendClientHandshake()

if (i != message.mSubprotocols.length - 1) {
mBuffer.write(", ");
}

to add comma only for separate strings.