[iagno] Bump Gtk+ required version to 3.13.4.

[Michael Catanzaro <mcatanzaro src gnome org>]

commit ae661bb1e4a5ce7649f3474f9a088d49946b36fd
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Tue Sep 16 06:08:42 2014 +0200

    Bump Gtk+ required version to 3.13.4.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=735053

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 46e82fc..f7207a8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -16,7 +16,7 @@ dnl Dependencies
 dnl ###########################################################################
 
 GLIB_REQUIRED=2.40.0
-GTK_REQUIRED=3.12
+GTK_REQUIRED=3.13.4
 RSVG_REQUIRED=2.32.0
 CANBERRA_GTK_REQUIRED=0.26