Added java doc for deprecated decoration

src/main/java/org/json/Cookie.java

@@ -13,12 +13,13 @@ Public Domain.
  * @author JSON.org
  * @version 2015-12-09
  */
-@Deprecated
 public class Cookie {
 
     /**
      * Constructs a new Cookie object.
+     * @deprecated (Utility class cannot be instantiated)
      */
+    @Deprecated()
     private Cookie() {
     }