Fix airspeed check in simulation

src/modules/sensors/sensors.cpp

@@ -1228,7 +1228,12 @@ Sensors::diff_pres_poll(struct sensor_combined_s &raw)
 
 		/* push data into validator */
 		_airspeed_validator.put(_airspeed.timestamp, _diff_pres.differential_pressure_raw_pa, _diff_pres.error_count, 100);
+		
+#ifdef __PX4_POSIX
+		_airspeed.confidence = 1.0f;
+#else
 		_airspeed.confidence = _airspeed_validator.confidence(hrt_absolute_time());
+#endif
 
 		/* don't risk to feed negative airspeed into the system */
 		_airspeed.indicated_airspeed_m_s = math::max(0.0f,