fix sitl with stupid ir simulation

sw/airborne/arch/sim/sim_ap.c

@@ -17,7 +17,6 @@
 #include "subsystems/nav.h"
 #include "firmwares/fixedwing/stabilization/stabilization_attitude.h"
 #include "firmwares/fixedwing/guidance/guidance_v.h"
-#include "subsystems/sensors/infrared.h"
 #include "commands.h"
 #include "firmwares/fixedwing/main_ap.h"
 #include "ap_downlink.h"

sw/airborne/subsystems/sensors/infrared.h

@@ -55,8 +55,10 @@
 #define IR_RollOfIrs(_ir1, _ir2) (_ir1 + _ir2)
 #define IR_PitchOfIrs(_ir1, _ir2) (-(_ir1) + _ir2)
 #else
+#ifndef SITL
 #error "You have to define either HORIZ_SENSOR_ALIGNED or HORIZ_SENSOR_TILTED in the IR section"
 #endif
+#endif
 /* Vertical sensor, TOP_SIGN gives positice values when it's warm on the bottom */
 #ifndef IR_TopOfIr
 #define IR_TopOfIr(_ir) (_ir)