Get rid of the race conditions by first checking to make sure that a duplicate...

Get rid of the race conditions by first checking to make sure that a duplicate node does not already exist before inserting nodes into the different caches.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@103978 13f79535-47bb-0310-9956-ffa450edef68