[gnome-taquin] Add a style class to close button.

[Arnaud B. <arnaudb src gnome org>]

commit b8d9532035073bf0e290aa47ad648b12f0931929
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Thu Aug 1 13:15:50 2019 +0200

    Add a style class to close button.
    
    Helps with Yaru theme.

 data/ui/base-headerbar.ui | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/data/ui/base-headerbar.ui b/data/ui/base-headerbar.ui
index 7f638a3..98452d4 100644
--- a/data/ui/base-headerbar.ui
+++ b/data/ui/base-headerbar.ui
@@ -68,6 +68,7 @@
             <property name="action-name">app.quit</property>
             <style>
               <class name="titlebutton"/>
+              <class name="close"/>
             </style>
             <child>
               <object class="GtkImage">