[gnome-music] Use margin_end instead of margin_right

[Vadim Rutkovsky <vrutkovsky src gnome org>]

commit 9ecc8a61694b7bf4ab65c9a69824a311ecf390c2
Author: Peter Shinners <pete shinners org>
Date:   Sun Jul 19 08:49:28 2015 -0700

    Use margin_end instead of margin_right
    
    The loading grid view was using margin_right to add some padding.
    As of Gtk 3.12 this is deprecated in favor of margin_end.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=752591

 gnomemusic/window.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gnomemusic/window.py b/gnomemusic/window.py
index 4d8d528..491a962 100644
--- a/gnomemusic/window.py
+++ b/gnomemusic/window.py
@@ -325,7 +325,7 @@ class Window(Gtk.ApplicationWindow):
     def _init_loading_notification(self):
         self.notification = Gd.Notification()
         self.notification.set_timeout(5)
-        grid = Gtk.Grid(valign=Gtk.Align.CENTER, margin_right=8)
+        grid = Gtk.Grid(valign=Gtk.Align.CENTER, margin_end=8)
         grid.set_column_spacing(8)
         spinner = Gtk.Spinner()
         spinner.start()