[gnome-games] ui: Stop using deprecated GtkImage:stock property

[Adrien Plazas <aplazas src gnome org>]

commit 76c077599a061207bec2f8d0d1d94ee3d9256cc4
Author: Alexander Mikhaylenko <exalm7659 gmail com>
Date:   Thu Jul 26 19:59:17 2018 +0500

    ui: Stop using deprecated GtkImage:stock property
    
    Replace it with 'icon_name' instead.

 data/ui/collection-box.ui | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/data/ui/collection-box.ui b/data/ui/collection-box.ui
index d3f14105..6c5c8383 100644
--- a/data/ui/collection-box.ui
+++ b/data/ui/collection-box.ui
@@ -130,6 +130,6 @@
   <object class="GtkImage" id="close_icon">
     <property name="visible">True</property>
     <property name="can_focus">False</property>
-    <property name="stock">gtk-close</property>
+    <property name="icon_name">window-close-symbolic</property>
   </object>
 </interface>