[fix] : Fixed desktop wallpaper

Author: Hayao0819

airootfs/etc/skel/.config/xfce4/xfconf/xfce-perchannel-xml/xfce4-desktop.xml

@@ -7,7 +7,7 @@
         <property name="workspace0" type="empty">
           <property name="color-style" type="int" value="0"/>
           <property name="image-style" type="int" value="5"/>
-          <property name="last-image" type="string" value="/usr/share/backgrounds/archlinux.jpg"/>
+          <property name="last-image" type="string" value="/usr/share/backgrounds/alter.png"/>
         </property>
         <property name="workspace1" type="empty">
           <property name="color-style" type="int" value="0"/>