Tracker: pre_arm_gps_check flag always true

AntennaTracker/AntennaTracker.pde

@@ -263,6 +263,7 @@ void setup()
 
     // antenna tracker does not use pre-arm checks or battery failsafe
     AP_Notify::flags.pre_arm_check = true;
+    AP_Notify::flags.pre_arm_gps_check = true;
     AP_Notify::flags.failsafe_battery = false;
 
     notify.init(false);