[BUG] Landing function

[lucasantoro]

Context

ROS: 1.14.5
OS: Melodic
Gazebo: 9
Ubuntu: 18.04
System Platform: [eg. X86_64]
Expected Behavior
Landing function, land the drone and disarm the drone

Current Behavior
at the end of you tutorial(original tutorial_1 in demo for offboard control), con.land, the drone start landing, but before touch ground, it stop and stay in hovering, while the console print land as first time, and then print land is not supported function

Screenshots