message: Update demo_turtlebot_mapping.launch
  Set Rtabmap/TimeThr to 0 by default
diff: <param name="RGBD/AngularUpdate" type="string" value="0.1"/> <!-- Update map only if the robot is moving -->
  <param name="RGBD/LinearUpdate" type="string" value="0.1"/> <!-- Update map only if the robot is moving -->
  <param name="RGBD/ProximityPathMaxNeighbors" type="string" value="0"/>
  - <param name="Rtabmap/TimeThr" type="string" value="700"/>
  + <param name="Rtabmap/TimeThr" type="string" value="0"/>
  <param name="Mem/RehearsalSimilarity" type="string" value="0.30"/>
  <param name="Reg/Force3DoF" type="string" value="true"/>
  <param name="GridGlobal/MinSize" type="string" value="20"/>
  