Fix test 517

Long description:

Test 517 was sometimes failing because the command to reset the test
generates a focus event which was not being properly ignored.

Now the correct event should always be tested.

To apply this patch, use:
curl http://cr.i3wm.org/patch/554/raw.patch | git am

@@ -68,7 +68,11 @@ is(@{$event->{current}->{nodes}}, 1, 'focus event gave the right number of windo

 # reset and try again

 $focus = AnyEvent->condvar;

-cmd 'workspace ws-left; move right';

+cmd 'workspace ws-left';

+$focus->recv;

+

+$focus = AnyEvent->condvar;

+cmd 'move right';

 $event = $focus->recv;

 ok($event, 'moving from workspace with one window triggered focus ipc event');

 is($event->{current}->{name}, 'ws-right', 'focus event gave the right workspace');