Disable DNS prefetching to solve CVE-2010-0464.
-Index: program/include/rcube_html_page.php
+Index: b/program/include/rcube_html_page.php
===================================================================
---- rcube/program/include/rcube_html_page.php (revision 3214)
-+++ rcube/program/include/rcube_html_page.php (working copy)
+--- a/program/include/rcube_html_page.php 2009-06-22 18:20:34.000000000 +0200
++++ b/program/include/rcube_html_page.php 2010-07-17 17:33:25.000000000 +0200
@@ -165,6 +165,13 @@
$__page_header.= $this->charset . '" />'."\n";
}