[master] remove superfluous assert and add ChangeLog entry

ChangeLog

@@ -1,3 +1,7 @@
+264.	[bug]       jerry
+	Fix a busy loop issue in notify-out.
+	(Trac 1001, git TBD)
+
 263.	[func]      jelte
 	Logging configuration can now also accept a * as a first-level
 	name (e.g. '*', or '*.cache'), indicating that every module

src/lib/python/isc/notify/tests/notify_out_test.py

@@ -385,7 +385,6 @@ class TestNotifyOut(unittest.TestCase):
         # nonblock_event will be cleared soon since there are no notifying zones.
         while (self._notify._nonblock_event.isSet()):
             pass
-        self.assertFalse(self._notify._nonblock_event.isSet())
 
         # send notify
         example_net_info = self._notify._notify_infos[('example.net.', 'IN')]
@@ -399,8 +398,8 @@ class TestNotifyOut(unittest.TestCase):
         example_net_info.notify_try_num = notify_out._MAX_NOTIFY_TRY_NUM
         while (self._notify._nonblock_event.isSet()):
             pass
-        self.assertFalse(self._notify._nonblock_event.isSet())
 
+        self.assertFalse(self._notify._nonblock_event.isSet())
         self._notify.shutdown()
         # nonblock_event should have been setted to stop waiting.
         self.assertTrue(self._notify._nonblock_event.isSet())