fix call palcement, suggested by jag on IRC, r=me

xpfe/components/prefwindow/resources/content/pref.xul

@@ -29,11 +29,12 @@
   function Startup()
     {
       hPrefWindow = new nsPrefWindow('panelFrame');  
-      hPrefWindow.init();
       
       if( !hPrefWindow )
         throw "failed to create prefwindow";
 
+      hPrefWindow.init();
+
       // If this call worked, we could center the window here:
       // centerWindowOnScreen();