Fixes a weird nulling call in playsound (#330)

fix potentially bad call

Author: Sun-Soaked

code/game/sound.dm

@@ -380,8 +380,10 @@ var/list/rummage_sound = list(\
 			if(dist > maxdistance)
 				if(!ishuman(M))
 					continue
-				else if(!M.stats.getPerk(PERK_EAR_OF_QUICKSILVER))
-					continue
+				else
+					var/mob/living/carbon/human/humanlistener = M
+					if(humanlistener.stats && !humanlistener.stats.getPerk(PERK_EAR_OF_QUICKSILVER))
+						continue
 			var/turf/T = get_turf(M)
 
 			if(T && (T.z == turf_source.z || zrange && abs(T.z - turf_source.z) <= zrange))