[dye] init.lua: Check for available flower colors before registering dye

recipes.

mods/materials/dye/init.lua

@@ -58,12 +58,20 @@ for _, row in ipairs(dyes) do
 		description = description,
 		groups = groups
 	})
+	
+	-- Compare color against flowers
+	if minetest.get_modpath('flowers') then
+		for I in pairs(flowers.colors) do
+			if name == flowers.colors[I] then
 				minetest.register_craft({
 					type = "shapeless",
 					output = item_name .. " 4",
 					recipe = {"group:flower,color_" .. name},
 				})
 			end
+		end
+	end
+end
 
 -- Manually add coal->black dye