message: updated euroc_datasets.launch
diff: <launch>
  +<!--
  +Examples:
  + F2M (default VO):
  + $ roslaunch rtabmap_ros euroc_datasets.launch
  + $ rosbag play -.-clock V1_01_easy.bag
  +
  + For MH sequences, we should set MH_seq to true because the ground truth source is different.
  + $ roslaunch rtabmap_ros euroc_datasets.launch MH_seq:=true
  + $ rosbag play -.-clock MH_01_easy.bag
  +
  + MSCKF (VIO):
  + $ roslaunch rtabmap_ros euroc_datasets.launch args:="-d RGBD/CreateOccupancyGrid false Odom/Strategy 8"
  + $ rosbag play -.-clock V1_01_easy.bag
  +
  + We need to ignore the first 24 seconds for correct VIO initialization (drone should not move).
  + $ roslaunch rtabmap_ros euroc_datasets.launch args:="-d RGBD/CreateOccupancyGrid false Odom/Strategy 8" MH_seq:=true
  + $ rosbag play -.-clock -s 24 MH_01_easy.bag
  +-->
  +
  <param name="use_sim_time" value="true"/>
  +<arg name="args" default="-d --RGBD/CreateOccupancyGrid false"/>
  <arg name="cfg" default=""/>
  <arg name="MH_seq" default="false"/> <!-- For MH sequences, the ground truth is coming from a different topic -->
  <arg name="rtabmapviz" default="true"/>
  <!-- RTAB-Map -->
  <include file="$(find rtabmap_ros)/launch/rtabmap.launch">
  - <arg name="rtabmap_args" value="--delete_db_on_start --RGBD/CreateOccupancyGrid false --Rtabmap/DetectionRate 1"/>
  + <arg name="args" value="$(arg args)"/>
  <arg name="stereo" value="true"/>
  <arg name="frame_id" value="base_link"/>
  <arg name="wait_for_transform" value="0.01"/>
  