Fix build with parallel make:

* server/Makefile.in: Revert changes to use an absolute path to
exports.c in some (but not all) places, and subsequent fallout.

PR: 24643
Reviewed by: Andr�� Malo, Jeff Trawick


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/APACHE_2_0_BRANCH@102285 13f79535-47bb-0310-9956-ffa450edef68