update the header that deals with the dependencies

toolkit/components/printing/content/printPreviewBindings.xml

@@ -38,7 +38,6 @@
 # ***** END LICENSE BLOCK ***** -->
 
 # this file depends on printUtils.js
-# caller must define the routine |exitPrintPreview| to restore the normal state
 
 <!DOCTYPE window SYSTEM "chrome://global/locale/printPreview.dtd">