bug: second take() hangs after disconnect during take() #104
Description
@Mons describes the following case when take() may hang.
Take a task from a connector (say, net.box), disconnect and connect again, try to take this task again. It is stated that the second take will (may?) hang.
It seems that something like this was fixed in xqueue here: moonlibs/xqueue@eb50150
Let's verify it, fix and cover with a test.