mod_perl: fixed to not use an hardcoded path to apxs

perl/mod_perl/mod_perl.conf

@@ -2,6 +2,7 @@
 # This copyright note is auto-generated by ./scripts/Create-CopyPatch.
 #
 # Filename: package/.../mod_perl/mod_perl.conf
+# Copyright (C) 2011 The OpenSDE Project
 # Copyright (C) 2004 - 2006 The T2 SDE Project
 #
 # More information can be found in the files COPYING and README.
@@ -11,4 +12,8 @@
 # the Free Software Foundation; version 2 of the License. A copy of the
 # GNU General Public License can be found in the file COPYING.
 # --- SDE-COPYRIGHT-NOTE-END ---
-plconfopt="MP_APXS=$root/opt/apache/sbin/apxs"
+
+# we depend on apache
+pkgprefix -t apache
+
+plconfopt="MP_APXS=$( pkgprefix -r sbindir apache)/apxs"