Fix mob heads not showing their texture when worn as head armor

mods/ITEMS/mcl_heads/init.lua

@@ -112,6 +112,8 @@ local function addhead(name, texture, desc, longdesc, rangemob, rangefactor)
 		_mcl_armor_mob_range_mob = rangemob,
 		_mcl_armor_mob_range_factor = rangefactor,
 		_mcl_armor_element = "head",
+		_mcl_armor_texture = "mcl_heads_" .. name .. ".png",
+		_mcl_armor_preview = "mcl_heads_" .. name .. "_preview.png",
 		_mcl_blast_resistance = 1,
 		_mcl_hardness = 1,
 	})