fix: add last line

Author: Jeongwon Na

implement-trie-prefix-tree/njngwn.java

@@ -62,4 +62,4 @@ public boolean startsWith(String prefix) {
  * obj.insert(word);
  * boolean param_2 = obj.search(word);
  * boolean param_3 = obj.startsWith(prefix);
- */
+ */