Spurious warnings at the end of ArvUvStream thread execution

[EmmanuelP]

At the end of the streaming, there are some warnings about failed transfers:

[10:07:08.995] 🆆 stream-thread> Leader transfer failed: transfer->status = 3
[10:07:08.995] 🆆 stream-thread> Payload transfer failed: transfer->status = 3
[10:07:08.996] 🆆 stream-thread> Payload transfer failed: transfer->status = 3

I guess they could be avoided by checking the streaming is ending.