Copter: fixed startup order of setting mavlink system ID

ArduCopter/system.cpp

@@ -112,6 +112,9 @@ void Copter::init_ardupilot()
 
     GCS_MAVLINK::set_dataflash(&DataFlash);
 
+    // identify ourselves correctly with the ground station
+    mavlink_system.sysid = g.sysid_this_mav;
+    
     // initialise serial ports
     serial_manager.init();
 
@@ -158,9 +161,6 @@ void Copter::init_ardupilot()
                          &g.fs_batt_voltage, &g.fs_batt_mah, &ap.value);
 #endif
 
-    // identify ourselves correctly with the ground station
-    mavlink_system.sysid = g.sysid_this_mav;
-
 #if LOGGING_ENABLED == ENABLED
     log_init();
 #endif