tests: make run-tests fail early if no channel is found...
tests: make run-tests fail early if no channel is found
I hit a weird corner case in run-tests where a test that caused an
exception to be raised was breaking everything with an unbound
variable error a few lines down because channel was never getting set
in this for loop. By adding an `else` clause to this for loop, we can
explode right away if we can't find a channel and give the developer a
better chance at figuring out what's going on.
