Merge r1070096 from trunk:

Log something nicer than "Internal error: pcfg_openfile() called
with NULL filename" if no password file is configured

Submitted by: sf
Reviewed by: igalic, rpluem 


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@1070648 13f79535-47bb-0310-9956-ffa450edef68