Copter: gps failsafe disabled until we get first 3d lock

ArduCopter/events.pde

@@ -137,8 +137,8 @@ static void failsafe_gps_check()
 {
     uint32_t last_gps_update_ms;
 
-    // return immediately if gps failsafe is disabled
-    if( !g.failsafe_gps_enabled ) {
+    // return immediately if gps failsafe is disabled or we have never had GPS lock
+    if (!g.failsafe_gps_enabled || !ap.home_is_set) {
         // if we have just disabled the gps failsafe, ensure the gps failsafe event is cleared
         if (failsafe.gps) {
             failsafe_gps_off_event();