Backport r1567580 from tomcat/trunk:
One more followup to r1567148
Assert that version number of written and re-parsed web.xml is as expected.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc7.0.x/trunk@1567582 13f79535-47bb-0310-9956-ffa450edef68