[dconf] bump Vala dependency

[Ryan Lortie <ryanl src gnome org>]

commit f7e414d5f53625b8d22908a3d8bbd6b7fcd84796
Author: Ryan Lortie <desrt desrt ca>
Date:   Fri Jan 27 12:22:53 2012 -0500

    bump Vala dependency
    
    Now that Vala 0.15.1 is out, hard depend on it.

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index bfe03ef..d91a930 100644
--- a/configure.ac
+++ b/configure.ac
@@ -13,7 +13,7 @@ AM_SILENT_RULES([yes])
 
 # Check for programs
 AC_PROG_CC
-AM_PROG_VALAC([0.11.7])
+AM_PROG_VALAC([0.15.1])
 
 # Use GSettings
 GLIB_GSETTINGS