[gtk] gtk-demo: Fix menubutton usage in listbox demo

[Matthias Clasen <matthiasc src gnome org>]

commit fc2dc82b708dd550bdaac180779dbb97333a654e
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue May 21 00:03:25 2019 +0000

    gtk-demo: Fix menubutton usage in listbox demo
    
    Menu buttons are no longer buttons, so they
    can't have children, and don't have a relief
    property.

 demos/gtk-demo/listbox.ui | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)
---
diff --git a/demos/gtk-demo/listbox.ui b/demos/gtk-demo/listbox.ui
index fa4a96df10..565f959568 100644
--- a/demos/gtk-demo/listbox.ui
+++ b/demos/gtk-demo/listbox.ui
@@ -171,13 +171,8 @@
                   <object class="GtkMenuButton" id="more-button">
                     <property name="can-focus">1</property>
                     <property name="receives-default">1</property>
-                    <property name="relief">none</property>
                     <property name="popup">menu1</property>
-                    <child>
-                      <object class="GtkLabel" id="label7">
-                        <property name="label" translatable="yes">More...</property>
-                      </object>
-                    </child>
+                    <property name="label" translatable="yes">More...</property>
                   </object>
                 </child>
               </object>