Fix make distcheck

This is broken subdir-objects is currently broken in automake.
See http://debbugs.gnu.org/cgi/bugreport.cgi?bug=13928 for the bug
status, enabling it will cause xfpm to fail a make distcheck build.

configure.ac.in

@@ -9,7 +9,9 @@ m4_define([xfpm_version], [xfpm_version_major().xfpm_version_minor().xfpm_versio
 AC_INIT([xfce4-power-manager],[xfpm_version],[http://bugzilla.xfce.org/])
 AC_PREREQ([2.69])
 
-AM_INIT_AUTOMAKE([1.8 dist-bzip2 tar-ustar no-dist-gzip subdir-objects])
+# subdir-objects is currently broken, see
+# http://debbugs.gnu.org/cgi/bugreport.cgi?bug=13928
+AM_INIT_AUTOMAKE([1.8 dist-bzip2 tar-ustar no-dist-gzip])
 AC_CONFIG_HEADERS([config.h])
 AM_MAINTAINER_MODE()
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])