[gitg] Update valac dependency

[Adam Dingle <adamd src gnome org>]

commit 3e405f889a2622d94d6f8a8d1658355db6f1bea6
Author: Adam Dingle <adam yorba org>
Date:   Sun Jun 9 08:44:15 2013 -0400

    Update valac dependency
    
    We now pass --gresource to valac, requiring a newer version of valac built from git master.

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 22bf03d..eb4426d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -37,7 +37,7 @@ AC_PROG_MAKE_SET
 AC_PATH_PROG(GZIP, gzip)
 
 AM_PATH_PYTHON([3.2.3])
-AM_PROG_VALAC([0.20.1.19])
+AM_PROG_VALAC([0.20.1.23])
 
 AC_PATH_PROG(GLIB_MKENUMS, glib-mkenums)
 AC_PATH_PROG(GLIB_COMPILE_RESOURCES, glib-compile-resources)