test_threads: remove socket.blocking.max.ms (deprecated, no-op)

Author: edenhill

tests/test_threads.py

@@ -39,7 +39,6 @@ def test_thread_safety():
 
     q = Queue()
     p = Producer({'socket.timeout.ms': 10,
-                  'socket.blocking.max.ms': 10,
                   'message.timeout.ms': 10})
 
     threads = list()