Bug#778744: workaround for dconf-editor crash

[john mullee]

fix for: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=784345

patch: /usr/share/glib-2.0/schemas/org.gnome.lightsoff.gschema.xml
-------8<-------
--- org.gnome.lightsoff.gschema.xml
+++ org.gnome.lightsoff.gschema.xml
@@ -2,7 +2,7 @@
   <schema id="org.gnome.lightsoff" path="/org/gnome/lightsoff/"
gettext-
domain="lightsoff">
     <key name="level" type="i">
       <default>1</default>
-      <range min="1" />
+      <range min="1" max="10" />
       <summary>The current level</summary>
       <description>The users's most recent level.</description>
     </key>
------->8-------