Add an erroe message when handler not found. This may be bogus,

since a change similar to this in 1.3.x generated many PR complaints.

Submitted by:	pthreads leftovers


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@83778 13f79535-47bb-0310-9956-ffa450edef68