Comment typo

Lib/test/test_socket.py

@@ -586,7 +586,7 @@ class BasicTCPTest(SocketConnectedTest):
         self.assertEqual(msg, MSG)
         # wait for _testShutdown to finish: on OS X, when the server
         # closes the connection the client also becomes disconnected,
-        # and the client's shutdown call will fail. (Issue #4937.)
+        # and the client's shutdown call will fail. (Issue #4397.)
         self.done.wait()
 
     def _testShutdown(self):