Support relative altitude for offboard global position setpoints
Support relative altitude for offboard global position setpoints

Previously the coordinate_frame flag for setpoint_target_global_int message was not handled, resulting in the vehicle to not handle altitude correctly. This commit handles the relative altitude correctly.
acfloria/Firmware,acfloria/Firmware,acfloria/Firmware,acfloria/Firmware,acfloria/Firmware,acfloria/Firmware,acfloria/Firmware