update notes on openni2_launch

Author: mikeferguson

README.md

@@ -14,7 +14,7 @@ Branching:
 - ROS2:
    - The [ros2](https://github.com/ros-drivers/openni2_camera/tree/ros2) branch supports Jazzy and later
    - The [iron](https://github.com/ros-drivers/openni2_camera/tree/iron) branch supports Humble to Iron
-   - openni2_launch has NOT been ported since proper lazy subscribers are still not possible in ROS2
+   - openni2_launch has NOT been ported yet
 
 ## Developer document
    - [docs.ros.org/openni2_launch](http://docs.ros.org/en/melodic/api/openni2_launch/html/)