Follow googlecartographer/cartographer_ros#454. (#65)

cartographer_turtlebot/configuration_files/demo_turtlebot.rviz

@@ -222,7 +222,6 @@ Visualization Manager:
       Value: true
     - Class: Submaps
       Enabled: true
-      Map frame: map
       Name: Submaps
       Submap query service: /submap_query
       Topic: /submap_list