Functionality this was testing has been removed.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/dbcp/trunk@1569096 13f79535-47bb-0310-9956-ffa450edef68
Now validation is using isValid() it needs a basic implementation here.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/dbcp/trunk@1569097 13f79535-47bb-0310-9956-ffa450edef68