fix test with regard to API change: kills are now blocking by default

greentest/test__greenletset.py

@@ -82,7 +82,7 @@ class Test(greentest.TestCase):
         s = pool.GreenletSet([p1, p2])
         assert len(s) == 2, s
         check(0, 0)
-        s.killone(p1)
+        s.killone(p1, block=False)
         check(0, 0)
         gevent.sleep(0)
         check(1, 0)
@@ -90,9 +90,9 @@ class Test(greentest.TestCase):
         check(1, 0)
         s.killone(p1)
         check(1, 0)
-        s.kill()
-        s.kill()
-        s.kill()
+        s.kill(block=False)
+        s.kill(block=False)
+        s.kill(block=False)
         check(1, 0)
         gevent.sleep(DELAY)
         check(1, 1)