Fix `configure --compat' to be more "compatible".

Submitted by: Ralf S. Engelschall
Reviewed by: Lars Eilebrecht, Ralf S. Engelschall


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@80995 13f79535-47bb-0310-9956-ffa450edef68