mobs:skeletons:sounds: fix code review issue and add todo

mods/ENTITIES/mobs_mc/skeleton+stray.lua

@@ -44,11 +44,13 @@ local skeleton = {
 			"mcl_bows_bow_0.png", -- wielded_item
 		}
 	},
+	-- TODO: change random to new api when min minetest version is 5.8
 	sounds = {
 		random = "mobs_mc_skeleton_random.2",
 		death = "mobs_mc_skeleton_death",
 		damage = "mobs_mc_skeleton_hurt",
 		distance = 16,
+	},
 	walk_velocity = 1.2,
 	run_velocity = 2.0,
 	damage = 2,