[model] Update configure.ac to require gtk-3.0

[Alberto Ruiz <aruiz src gnome org>]

commit 600b2a01b9831b1cec46817bf191a9caeb31deeb
Author: Alberto Ruiz <aruiz gnome org>
Date:   Fri Oct 26 22:43:11 2012 +0200

    Update configure.ac to require gtk-3.0

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 47f4c0f..e0dd4d6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -8,7 +8,7 @@ AC_PROG_CC
 
 PKG_CHECK_MODULES(introspection, gobject-introspection-1.0 >= 0.6.3)
 PKG_CHECK_MODULES(gobject, gobject-2.0)
-PKG_CHECK_MODULES(gtk, gtk+-2.0)
+PKG_CHECK_MODULES(gtk, gtk+-3.0)
 
 AC_SUBST(girdir, ${datadir}/gir-1.0)
 AC_SUBST(typelibdir, ${libdir}/girepository-1.0)