MMIs can now whisper without talking on the radio (#35738)

* MMIs can now whisper without talking on the radio

Fixes #35638.

* Otherwise, call super

code/modules/mob/living/brain/say.dm

@@ -14,11 +14,13 @@
 	return ..() | SPAN_ROBOT
 
 /mob/living/brain/radio(message, message_mode, list/spans, language)
-	if(message_mode && istype(container, /obj/item/device/mmi))
+	if(message_mode == MODE_HEADSET && istype(container, /obj/item/device/mmi))
 		var/obj/item/device/mmi/R = container
 		if(R.radio)
 			R.radio.talk_into(src, message, , get_spans(), language)
 			return ITALICS | REDUCE_RANGE
+	else
+		return ..()
 
 /mob/living/brain/lingcheck()
 	return LINGHIVE_NONE