ArduCopter: stop streaming trying SIM_STATE messages outside sim

ArduCopter/GCS_Mavlink.cpp

@@ -531,7 +531,9 @@ static const ap_message STREAM_RC_CHANNELS_msgs[] = {
 };
 static const ap_message STREAM_EXTRA1_msgs[] = {
     MSG_ATTITUDE,
+#if AP_SIM_ENABLED
     MSG_SIMSTATE,
+#endif
     MSG_AHRS2,
     MSG_PID_TUNING // Up to four PID_TUNING messages are sent, depending on GCS_PID_MASK parameter
 };