return to default pose after hydra disconnect

Fix for worklist bug 19848:

BUG: When I disconnect the hydra controllers, hands do not return to neutral
https://worklist.net/19848

The code that would set the palms inactive was being bypassed by a new check that would notice that the sixense controllers weren't even connected.  I moved the check up before the early exit.
This moved up from down below so it would actually be called before an early exit for disconnected hydras.