APM: updates for new GPS detection

ArduPlane/system.pde

@@ -193,7 +193,6 @@ static void init_ardupilot()
 	g_gps = &g_gps_driver;
     // GPS Initialization
     g_gps->init(GPS::GPS_ENGINE_AIRBORNE_4G);
-    g_gps->callback = mavlink_delay;
 
     //mavlink_system.sysid = MAV_SYSTEM_ID;				// Using g.sysid_this_mav
     mavlink_system.compid = 1;          //MAV_COMP_ID_IMU;   // We do not check for comp id