[gnome-session] configure: Fix with/have systemd confusion

[Colin Walters <walters src gnome org>]

commit f6c39b3c63e085b815904332e9ab8e54cf0ab01c
Author: Colin Walters <walters verbum org>
Date:   Tue Jan 15 08:35:21 2013 -0500

    configure: Fix with/have systemd confusion
    
    This was harmless before since nothing was using the conditional, but
    a later patch will.

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 0656ec9..e88e0cf 100644
--- a/configure.ac
+++ b/configure.ac
@@ -132,7 +132,7 @@ fi
 AC_SUBST(SYSTEMD_CFLAGS)
 AC_SUBST(SYSTEMD_LIBS)
 
-AM_CONDITIONAL(HAVE_SYSTEMD, [test "$with_systemd" = "yes"], [Using systemd])
+AM_CONDITIONAL(HAVE_SYSTEMD, [test "$enable_systemd" = "yes"], [Using systemd])
 
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 dnl X development libraries check