[pybliographer/wip/gtk3] utils: Fix call to gettext

[Germán Poo-Caamaño <gpoo src gnome org>]

commit e5933d3d915aba2e08f32b54380850780e0550fd
Author: Germán Poo-Caamaño <gpoo gnome org>
Date:   Tue Oct 10 10:31:50 2017 -0300

    utils: Fix call to gettext

 Pyblio/GnomeUI/Utils.py |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/Pyblio/GnomeUI/Utils.py b/Pyblio/GnomeUI/Utils.py
index 10662db..6f9b46e 100644
--- a/Pyblio/GnomeUI/Utils.py
+++ b/Pyblio/GnomeUI/Utils.py
@@ -25,6 +25,8 @@
 import os
 import gi
 
+from gettext import gettext as _
+
 gi.require_versions({'GConf': '2.0'})
 from gi.repository import Gtk, Pango, Gdk, GConf