Fix the config parser so that if there is no current node, and we are

evaluating an EXEC_ON_READ directive, and the directive's sub_tree is empty,
we don't try to set the node's parent pointer.  This stops a seg fault.
Submitted by:	Jeff Trawick


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@85269 13f79535-47bb-0310-9956-ffa450edef68