Flowers: Fix misaligned waterlily texture

Previously waterlily has misaligned top and bottom textures and looks
different when viewed from below.

This also hides the flower in bottom texture.

mods/flowers/init.lua

@@ -217,7 +217,7 @@ minetest.register_node("flowers:waterlily", {
 	drawtype = "nodebox",
 	paramtype = "light",
 	paramtype2 = "facedir",
-	tiles = {"flowers_waterlily.png"},
+	tiles = {"flowers_waterlily.png", "flowers_waterlily_bottom.png"},
 	inventory_image = "flowers_waterlily.png",
 	wield_image = "flowers_waterlily.png",
 	liquids_pointable = true,