message: rtabmap:odomUpdate(): detect correctly zero timestamp
diff: @@ -993,7 +993,10 @@ bool CoreWrapper::odomUpdate(const nav_msgs::OdometryConstPtr & odomMsg, ros::Ti
  Transform odom = rtabmap_ros::transformFromPoseMsg(odomMsg->pose.pose);
  if(!odom.isNull())
  {
  - Transform odomTF = rtabmap_ros::getTransform(odomMsg->header.frame_id, frameId_, stamp, tfListener_, waitForTransform_?waitForTransformDuration_:0.0);
  + Transform odomTF;
  + if(!stamp.isZero()) {
  + odomTF = rtabmap_ros::getTransform(odomMsg->header.frame_id, frameId_, stamp, tfListener_, waitForTransform_?waitForTransformDuration_:0.0);
  + }
  if(odomTF.isNull())
  {
  static bool shown = false;
  