commander: neutral beep on mission with warning

When a mission is uploaded we should beep consistenly:
- valid -> positive
- warn -> neutral
- invalid -> negative

Before this, it was:
- valid -> positive
- warn -> negative
- invalid -> negative

src/modules/commander/Commander.cpp

@@ -2089,7 +2089,7 @@ Commander::run()
 
 					} else if (mission_result.warning) {
 						/* the mission has a warning */
-						tune_mission_fail(true);
+						tune_mission_warn(true);
 
 					} else {
 						/* the mission is valid */

src/modules/commander/commander_helper.cpp

@@ -206,6 +206,16 @@ void tune_mission_ok(bool use_buzzer)
 	blink_msg_end = hrt_absolute_time() + BLINK_MSG_TIME;
 	rgbled_set_color_and_mode(led_control_s::COLOR_GREEN, led_control_s::MODE_BLINK_FAST);
 
+	if (use_buzzer) {
+		set_tune(tune_control_s::TUNE_ID_NOTIFY_POSITIVE);
+	}
+}
+
+void tune_mission_warn(bool use_buzzer)
+{
+	blink_msg_end = hrt_absolute_time() + BLINK_MSG_TIME;
+	rgbled_set_color_and_mode(led_control_s::COLOR_YELLOW, led_control_s::MODE_BLINK_FAST);
+
 	if (use_buzzer) {
 		set_tune(tune_control_s::TUNE_ID_NOTIFY_NEUTRAL);
 	}

src/modules/commander/commander_helper.h

@@ -64,6 +64,7 @@ void set_tune_override(int tune);
 void set_tune(int tune);
 void tune_home_set(bool use_buzzer);
 void tune_mission_ok(bool use_buzzer);
+void tune_mission_warn(bool use_buzzer);
 void tune_mission_fail(bool use_buzzer);
 void tune_positive(bool use_buzzer);
 void tune_neutral(bool use_buzzer);