Observer huds now only trigger for mobs (#20490)

* Observer huds now only trigger for mobs

getpois can return items that are not mobs, such as the capture the flag
machinery, so we avoid trying to set the hud for these items

* add missing bracket

code/modules/mob/mob.dm

@@ -499,8 +499,8 @@ var/next_mob_id = 0
 		return
 
 	var/mob/mob_eye = creatures[eye_name]
-
-	if(client && mob_eye)
+	//Istype so we filter out points of interest that are not mobs
+	if(client && mob_eye && istype(mob_eye))
 		client.eye = mob_eye
 		if(isobserver(src))
 			src.client.screen = list()