Confirmations in highPrioQueue could act on lowPrioQueue

[juwiefer-btc]

From a code review, without really having "reproduced" this as an error, a confirmation APDU could result in a random lowPrioQueue entry to be confirmed, if the confirmation is about a highPrioQueue entry.

In ClientConnection.cs:sendNextHighPriorityASDU(), it should read:

                         sentASDUs[currentIndex].queueIndex = -1;