Broken connection during connect treated as rejected connection by client

If a Paho client connects, then a client with the same clientid connects from a different location immediately afterwards (before the CONNACK has been sent from the server), the new client will take over the original client's state, and the original client will be disconnected. The original client seems to be treating this early disconnection as a rejection of the original connection attempt, so if the default properties are being used a 3.1.1 client will then try to step down and send a 3.1 connect instead - this 3.1 connect packet will then take over the existing client (that was the second one to connect) with a 3.1 connection.

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- [ ] Bug exists Release Version 1.2.0 ( Master Branch)
- [ ] Bug exists in MQTTv3 Client on Snapshot Version 1.2.1-SNAPSHOT (Develop Branch)
- [ ] Bug exists in MQTTv5 Client on Snapshot Version 1.2.1-SNAPSHOT (Develop Branch)

If this is a bug regarding the Android Service, please raise the bug here instead: https://github.com/eclipse/paho.mqtt.android/issues/new