A small optimization to the node setup

[marcelveldt]

If you have issues in your Thread network and/or multiple misbehaving devices we get trapped into a deadlock situation if we have 5 nodes stuck in setup. In that case no devices will be setup at all.

This changes the logic a tiny bit so we still use a semaphore to somewhat throttle the burst of traffic that the setup generates on the thread network but back out of it in case a node hangs in there.

• Use set-up semaphore only for Thread devices
• Release semaphore when we detect a node hangs in setup