replay_gain: trigger OPTIONS idle event on mode change

src/replay_gain.c

@@ -24,6 +24,7 @@
 #include "conf.h"
 #include "audio_format.h"
 #include "pcm_volume.h"
+#include "idle.h"
 
 #include <glib.h>
 
@@ -75,6 +76,8 @@ replay_gain_set_mode_string(const char *p)
 	else
 		return false;
 
+	idle_add(IDLE_OPTIONS);
+
 	return true;
 }