Upgrade to servlet 2.5
Current services parent (1.2.2) defines that the managed servlet API is the 2.4. Since 2005 servlet 2.5 exists. It is the default one for Tomcat 6. (While tomcat 5.5 still uses 2.4 and tomcat 7.0 uses the 3.0).
Since main servlet container now rely on 2.5 and higher version we can safely switch to 2.5. (Ok for Tomcat 6 and 7, Jetty 6, 7 and 8...)