[tcp] Retransmit Routine Shouldn't Remove Data from Unacknowledged Queue

[BrianZill]

Description

The existing retransmit routine has a fatal flaw, it is removing data from the unacknowledged queue. This breaks our logic that tracks unacknowledged data. Instead, retransmit() should be retransmitting the data without removing it from the queue.

Since this bug is very serious, I've disabled the calling of retransmit(). This should be reenabled when this bug is fixed.