[gtk+] gtk4-demo: Fix font-features UI file

[Timm Bäder <baedert src gnome org>]

commit 827d04c482eafa48d77e9ba4f97d488961d3f075
Author: Timm Bäder <mail baedert org>
Date:   Tue Dec 19 09:46:27 2017 +0100

    gtk4-demo: Fix font-features UI file

 demos/gtk-demo/font-features.ui |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/demos/gtk-demo/font-features.ui b/demos/gtk-demo/font-features.ui
index b3da993..aae2615 100644
--- a/demos/gtk-demo/font-features.ui
+++ b/demos/gtk-demo/font-features.ui
@@ -8,7 +8,7 @@
     <child type="titlebar">
       <object class="GtkHeaderBar">
         <property name="visible">1</property>
-        <property name="show_close_button">1</property>
+        <property name="show-title-buttons">1</property>
         <property name="title">Font Features</property>
         <child>
           <object class="GtkButton" id="reset">