[gnome-control-center] window: Use the sidebar style class on sidebar separators

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 64ac458804e51be6e8096e3cd8f50b973d9b31ab
Author: Adrien Plazas <kekun plazas laposte net>
Date:   Thu Oct 25 14:34:34 2018 +0200

    window: Use the sidebar style class on sidebar separators
    
    This adds the sidebar style class to the sidebar separators to keep them
    styled correctly.

 shell/cc-window.ui | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/shell/cc-window.ui b/shell/cc-window.ui
index acab5126a..67c71e9d0 100644
--- a/shell/cc-window.ui
+++ b/shell/cc-window.ui
@@ -84,6 +84,9 @@
             <property name="visible">True</property>
             <property name="can_focus">False</property>
             <property name="orientation">vertical</property>
+            <style>
+              <class name="sidebar"/>
+            </style>
           </object>
           <packing>
             <property name="expand">False</property>
@@ -202,6 +205,9 @@
                 <property name="visible">True</property>
                 <property name="can_focus">False</property>
                 <property name="orientation">vertical</property>
+                <style>
+                  <class name="sidebar"/>
+                </style>
               </object>
             </child>
             <child>