[gnome-calculator] Depend on unreleased Vala 0.23

[Michael Catanzaro <mcatanzaro src gnome org>]

commit a1300558e05e47449afb73032439586f959d69f8
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Mon Nov 25 13:01:03 2013 -0600

    Depend on unreleased Vala 0.23
    
    Needed for the GTK+ 3.11.2 bindings.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=705909

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 32436d5..13d5f18 100644
--- a/configure.ac
+++ b/configure.ac
@@ -6,7 +6,7 @@ AM_SILENT_RULES([yes])
 AM_MAINTAINER_MODE
 GNOME_MAINTAINER_MODE_DEFINES
 
-AM_PROG_VALAC([0.18.0])
+AM_PROG_VALAC([0.23.0])
 AM_PROG_CC_C_O
 
 AC_PATH_PROG(GLIB_COMPILE_RESOURCES, glib-compile-resources)