[gnome-music] Make the close button consistent with a standard headerbar

[Vadim Rutkovsky <vrutkovsky src gnome org>]

commit 1f514609007ffa4909ecfb3c4b1c0228ff96e159
Author: Yosef Or Boczko <yoseforb gmail com>
Date:   Wed Sep 18 14:24:44 2013 +0300

    Make the close button consistent with a standard headerbar
    
    https://bugzilla.gnome.org/show_bug.cgi?id=708279

 data/headerbar.ui.in |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/data/headerbar.ui.in b/data/headerbar.ui.in
index f22a102..e60fc65 100644
--- a/data/headerbar.ui.in
+++ b/data/headerbar.ui.in
@@ -157,6 +157,7 @@
         <property name="sensitive">True</property>
         <style>
           <class name="image-button"/>
+          <class name="titlebutton"/>
         </style>
         <child>
           <object class="GtkImage" id="close-button-image">