Add cobweb sounds, fix indentation

mods/ITEMS/mcl_core/nodes.lua

@@ -1917,6 +1917,7 @@ minetest.register_node("mcl_core:cobweb", {
 	walkable = false,
 	groups = {swordy_cobweb=1,shearsy=1, deco_block=1},
 	drop = "mcl_mobitems:string",
+	sounds = mcl_sounds.node_sound_leaves_defaults(),
 	_mcl_blast_resistance = 20,
 	_mcl_hardness = 4,
 })