validateQos() Crash

Please fill out the form below before submitting, thank you!

- [x ] Bug exists Release Version 1.1.1 ( Master Branch)
- [ ] Bug exists in Snapshot Version 1.1.2-SNAPSHOT (Develop Branch)

This is the stacktrace:
```java
Fatal Exception: java.lang.IllegalArgumentException
at org.eclipse.paho.client.mqttv3.MqttMessage.validateQos(MqttMessage.java:41)
at org.eclipse.paho.client.mqttv3.MqttMessage.setQos(MqttMessage.java:181)
at org.eclipse.paho.client.mqttv3.internal.wire.MqttPublish.(MqttPublish.java)
at org.eclipse.paho.client.mqttv3.internal.wire.MqttWireMessage.createWireMessage(MqttWireMessage.java:193)
at org.eclipse.paho.client.mqttv3.internal.wire.MqttWireMessage.createWireMessage(MqttWireMessage.java:167)
at org.eclipse.paho.client.mqttv3.internal.wire.MqttInputStream.readMqttWireMessage(MqttInputStream.java:119)
at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:116)
at java.lang.Thread.run(Thread.java:841)
```

I understand that `validateQos()` is receiving an invalid QOS, but is the client trying to publish that invalid QOS message or is it received on the client in a malformed way from the broker?

As per my understanding of this stack trace, the client received a msg which it failed to convert into a valid MqttMessage due to an invalid QOS. Is that right?
It's a confusing stacktrace :(