master: do not die if neoctl asks the master directly for cluster state

Of course, neoctl should only connect to the admin, but in case of user mistake
the queried node should not die. Ideally, all other commands should be checked.

neo/master/handlers/__init__.py

@@ -58,7 +58,6 @@ class MasterHandler(EventHandler):
         )
 
     def askClusterState(self, conn):
-        assert conn.getUUID() is not None
         state = self.app.getClusterState()
         conn.answer(Packets.AnswerClusterState(state))