message: Update demo_hector_mapping.launch
diff: <param name="rgb/image_transport" type="string" value="compressed"/>
  <param name="depth/image_transport" type="string" value="compressedDepth"/>
  - <!-- As hector doesn't provide compatible covariance in the odometry topic, don't use the topic and fix the covariance -->
  + <!-- As hector doesn't provide compatible covariance in the odometry topic -->
  <param if="$(arg hector)" name="odom_frame_id" type="string" value="hector_map"/>
  <remap unless="$(arg hector)" from="odom" to="/scanmatch_odom"/>
  