Rover: add param conversion from MAG_ENABLE to COMPASS_ENABLED

APMrover2/GCS_Rover.cpp

@@ -63,7 +63,6 @@ void GCS_Rover::update_vehicle_sensor_status_flags(void)
     }
 
     AP_AHRS &ahrs = AP::ahrs();
-    const Compass &compass = AP::compass();
 
     if (AP::compass().enabled() && AP::compass().healthy(0) && ahrs.use_compass()) {
         control_sensors_health |= MAV_SYS_STATUS_SENSOR_3D_MAG;

APMrover2/Parameters.cpp

@@ -763,6 +763,8 @@ const AP_Param::ConversionInfo conversion_table[] = {
     { Parameters::k_param_serial2_baud,       0,      AP_PARAM_INT16, "SERIAL2_BAUD" },
     { Parameters::k_param_throttle_min_old,   0,      AP_PARAM_INT8,  "MOT_THR_MIN" },
     { Parameters::k_param_throttle_max_old,   0,      AP_PARAM_INT8,  "MOT_THR_MAX" },
+
+    { Parameters::k_param_compass_enabled_deprecated,       0,      AP_PARAM_INT8, "COMPASS_ENABLE" },
 };
 
 void Rover::load_parameters(void)