Reduce FindBugs warnings
Male it explicit that the exception is being ignored

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/dbcp/trunk@1557576 13f79535-47bb-0310-9956-ffa450edef68
Reduce FindBugs warnings
Use synchronisation consistently

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/dbcp/trunk@1557577 13f79535-47bb-0310-9956-ffa450edef68