Fix setRecipes(List) not setting Knowledge Book recipes.

Iterator source for recipe NamespacedKeys is changed to use method
parameter 'recipes' specifying recipes to be added, rather than class
property 'recipes', to which recipes are added.

src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaKnowledgeBook.java

@@ -116,7 +116,7 @@ public class CraftMetaKnowledgeBook extends CraftMetaItem implements KnowledgeBo
     @Override
     public void setRecipes(List<NamespacedKey> recipes) {
         this.recipes.clear();
-        for (NamespacedKey recipe : this.recipes) {
+        for (NamespacedKey recipe : recipes) {
             addRecipe(recipe);
         }
     }