Make dry shrubs buildable_to

mods/default/nodes.lua

@@ -1159,6 +1159,7 @@ minetest.register_node("default:dry_shrub", {
 	wield_image = "default_dry_shrub.png",
 	paramtype = "light",
 	walkable = false,
+	buildable_to = true,
 	groups = {snappy=3,flammable=3,attached_node=1},
 	sounds = default.node_sound_leaves_defaults(),
 	selection_box = {