[gtk+/wip/baedert/box] gtk4-demo: Fix builder demo

[Timm Bäder <baedert src gnome org>]

commit f5f605418f60efba87d14388a88c5077eae621bb
Author: Timm Bäder <mail baedert org>
Date:   Wed Oct 19 20:48:11 2016 +0200

    gtk4-demo: Fix builder demo

 demos/gtk-demo/demo.ui |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/demos/gtk-demo/demo.ui b/demos/gtk-demo/demo.ui
index bbed319..cfd0650 100644
--- a/demos/gtk-demo/demo.ui
+++ b/demos/gtk-demo/demo.ui
@@ -35,8 +35,9 @@
     <property name="default_width">440</property>
     <property name="title" translatable="yes">Builder</property>
     <child>
-      <object class="GtkVBox" id="vbox1">
+      <object class="GtkBox" id="vbox1">
         <property name="visible">1</property>
+        <property name="orientation">vertical</property>
         <child>
           <object class="GtkMenuBar" id="menubar1">
             <property name="visible">1</property>