Merge pull request #3504 from minrk/fixsession

don't use parent=self in handlers

handlers aren't configurable, so shouldn't be passed as parent.

closes  #3502

IPython/html/base/zmqhandlers.py

@@ -84,7 +84,7 b' class AuthenticatedZMQStreamHandler(ZMQStreamHandler, IPythonHandler):'
 
     def open(self, kernel_id):
         self.kernel_id = kernel_id.decode('ascii')
-        self.session = Session(parent=self)
+        self.session = Session(config=self.config)
         self.save_on_message = self.on_message
         self.on_message = self.on_first_message