[gtk+] gtk3-demo: Drop .sidebar class

[Matthias Clasen <matthiasc src gnome org>]

commit 7b3cda2cd5160c4d8d13c7346836aad97d52ce8c
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Nov 5 09:09:33 2015 -0500

    gtk3-demo: Drop .sidebar class
    
    This makes no visual difference at all, and the .sidebar class
    is causing some complications with the current CSS node transition.

 demos/gtk-demo/main.ui |    3 ---
 1 files changed, 0 insertions(+), 3 deletions(-)
---
diff --git a/demos/gtk-demo/main.ui b/demos/gtk-demo/main.ui
index 7037f2f..793bbde 100644
--- a/demos/gtk-demo/main.ui
+++ b/demos/gtk-demo/main.ui
@@ -72,9 +72,6 @@
                 <property name="can_focus">1</property>
                 <property name="hscrollbar_policy">never</property>
                 <property name="min_content_width">150</property>
-                <style>
-                  <class name="sidebar"/>
-                </style>
                 <child>
                   <object class="GtkTreeView" id="treeview">
                     <property name="visible">1</property>