[gtk+] gtk-demo: ui: Replace leftover uses of Box:expand

[Daniel Boles <dboles src gnome org>]

commit 8ddadecb5728120cb3efb92f91d071f9c6bc1a9f
Author: Daniel Boles <dboles src gnome org>
Date:   Sat May 13 18:08:51 2017 +0100

    gtk-demo: ui: Replace leftover uses of Box:expand
    
    commit 5729ea7744c2a41ae8fb833db6690a6aa5ad7a84 skipped these

 demos/gtk-demo/font-features.ui |   10 ++++------
 demos/gtk-demo/theming.ui       |    5 ++---
 2 files changed, 6 insertions(+), 9 deletions(-)
---
diff --git a/demos/gtk-demo/font-features.ui b/demos/gtk-demo/font-features.ui
index 3906b8c..a47e922 100644
--- a/demos/gtk-demo/font-features.ui
+++ b/demos/gtk-demo/font-features.ui
@@ -1647,15 +1647,13 @@
                 <property name="valign">end</property>
                 <property name="width-chars">50</property>
                 <property name="max-width-chars">50</property>
+                <property name="hexpand">1</property>
+                <property name="vexpand">1</property>
               </object>
-              <packing>
-                <property name="expand">1</property>
-              </packing>
             </child>
+            <property name="hexpand">1</property>
+            <property name="vexpand">1</property>
           </object>
-          <packing>
-            <property name="expand">1</property>
-          </packing>
         </child>
       </object>
     </child>
diff --git a/demos/gtk-demo/theming.ui b/demos/gtk-demo/theming.ui
index 7d3c103..ed25cb0 100644
--- a/demos/gtk-demo/theming.ui
+++ b/demos/gtk-demo/theming.ui
@@ -252,10 +252,9 @@
             <property name="visible">1</property>
             <property name="label">Plain</property>
             <property name="halign">end</property>
+            <property name="hexpand">1</property>
+            <property name="vexpand">1</property>
           </object>
-          <packing>
-            <property name="expand">1</property>
-          </packing>
         </child>
         <child>
           <object class="GtkButton">