client.send results in "Cannot read property 'length' of undefined" TypeError

Hi all,

In my onConnect cb I'm simply trying to send a "Hello" message on the topic I subscribed to just before I send it. However, for some reason it's giving me a TypeError: Cannot read property length of undefined, which point me to this section:

```
/**
* Called when the underlying websocket has received a complete packet.
* @ignore
*/
ClientImpl.prototype._on_socket_message = function (event) {
this._trace("Client._on_socket_message", event.data);
var messages = this._deframeMessages(event.data);
for (var i = 0; i < messages.length; i+=1) {
this._handleMessage(messages[i]);
}
};
```
So messages is undefined apparently.
I'm hoping somebody encountered this before or could point me in the right direction.
Or perhaps it's a bug, but seems unlikely since nobody's having this issue as of yet.

I'm using React 15.4.1 with WebPack and npm package paho-mqtt 1.0.4
I thought it might be related to below issue 150. However the proposed solution didn't help me:
https://github.com/eclipse/paho.mqtt.javascript/issues/150

What I'm doing is real straightforward:
```
this.client.connect(
{
userName: this.userName,
password: this.password,
useSSL: true,
onSuccess: this.onConnect.bind(this),
onFailure: this.showConnectionErrorMessage,
willMessage: this.lastWill
}
);
```
And my onConnect handling:
```
onConnect() {
console.log('onSucces');
this.client.subscribe(this.broadcastTopic);
this.client.onMessageArrived = this.onMessageArrived;

// I tried setting a timeout on my first attempt
// setTimeout( () => {
let message = new Paho.Message("Hello");
message.destinationName = this.broadcastTopic;

this.client.publish(message);
// I also tried the direct way of sending a message
// this.client.send(this.broadcastTopic, 'World')
// }, 3000)
},
onMessageArrived(message) {
console.log('onMessageArrived');
console.log(message);
},
```
Thanks all!