apmplanner treats a takeoff mission as navigation to coordinates to 0,0

[marcmerlin]

As explained in https://github.com/ArduPilot/ardupilot/issues/2811, both mission planner and Qgroundcontrol treat a takeoff mission as if it were navigation to gps coordinates 0,0, drawing a long line to nowhere. Apparently only mission planner gets this right as pointed out by @magicrub