Clean-up: remove DecorationLayout from xsettings-xml (MR 9)

It is the same like in upstream config in /etc/xdg/xfce4. Therefore
no need to specify it again.

config/xfce4/xfconf/xfce-perchannel-xml/xsettings.xml

@@ -4,9 +4,6 @@
   <property name="Xft" type="empty">
     <property name="DPI" type="int" value="96"/>
   </property>
-  <property name="Gtk" type="empty">
-    <property name="DecorationLayout" type="string" value="menu:minimize,maximize,close"/>
-  </property>
   <property name="Net" type="empty">
     <property name="IconThemeName" type="string" value="Faenza-Ambiance"/>
   </property>