fixed shut down bug; the connection must be rolled back before closing

git-svn-id: https://svn.apache.org/repos/asf/incubator/activemq/trunk@424542 13f79535-47bb-0310-9956-ffa450edef68

activemq-core/src/main/java/org/apache/activemq/store/jdbc/DefaultDatabaseLocker.java

@@ -71,6 +71,7 @@ public class DefaultDatabaseLocker implements DatabaseLocker {
 
     public void stop() throws Exception {
         if (connection != null) {
+            connection.rollback();
             connection.close();
         }
     }