AntennaTracker: implement MAV_CMD_REQUEST_AUTOPILOT_CAPABILITIES

AntennaTracker/GCS_Mavlink.pde

@@ -595,6 +595,14 @@ void GCS_MAVLINK::handleMessage(mavlink_message_t* msg)
                 break;
             }
 
+            case MAV_CMD_REQUEST_AUTOPILOT_CAPABILITIES: {
+                if (packet.param1 == 1) {
+                    gcs[chan-MAVLINK_COMM_0].send_autopilot_version();
+                    result = MAV_RESULT_ACCEPTED;
+                }
+                break;
+            }
+
             default:
                 break;
         }