Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=54256
Improve error reporting when a JAR file fails extension validation by including the name of the JAR file in the exception.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc7.0.x/trunk@1428084 13f79535-47bb-0310-9956-ffa450edef68