Update TypeHandler.java

Add throws missing doc line from openFile function
diff --git a/src/main/java/org/apache/commons/cli/TypeHandler.java b/src/main/java/org/apache/commons/cli/TypeHandler.java
index ad96b10..68b4f02 100644
--- a/src/main/java/org/apache/commons/cli/TypeHandler.java
+++ b/src/main/java/org/apache/commons/cli/TypeHandler.java
@@ -229,6 +229,7 @@
      *
      * @param str the file location
      * @return The file input stream represented by <code>str</code>.
+     * @throws ParseException if the file is not exist or not readable
      */
     public static FileInputStream openFile(String str) throws ParseException
     {