Fix showcase lastNameColumn/ageColumn typo

Repost of 1602803.
Thanks Stephen!

Review at http://gwt-code-reviews.appspot.com/1728804

Review by: rdayal@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@11026 8db76d5a-ed1c-0410-87a9-c151d255dfc7

samples/showcase/src/com/google/gwt/sample/showcase/client/content/cell/CwDataGrid.java

diff --git a/samples/showcase/src/com/google/gwt/sample/showcase/client/content/cell/CwDataGrid.java b/samples/showcase/src/com/google/gwt/sample/showcase/client/content/cell/CwDataGrid.java
index 7e6149a..322b465 100644
--- a/samples/showcase/src/com/google/gwt/sample/showcase/client/content/cell/CwDataGrid.java
+++ b/samples/showcase/src/com/google/gwt/sample/showcase/client/content/cell/CwDataGrid.java
@@ -276,7 +276,7 @@
         return object.getAge();
       }
     };
-    lastNameColumn.setSortable(true);
+    ageColumn.setSortable(true);
     sortHandler.setComparator(ageColumn, new Comparator<ContactInfo>() {
       @Override
       public int compare(ContactInfo o1, ContactInfo o2) {