Fix URL to list of public name servers in dns.cgi

We have only one english wiki, so the link to the list of public
dns servers can point directly to the right page.
(The link was also not correct).

Fixes: #11191

Signed-off-by: Jonatan Schlag <jonatan.schlag@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

html/cgi-bin/dns.cgi

@@ -91,7 +91,7 @@ print <<END
 
 <table border="0"  width='100%'>
   <tr>
-    <td colspan="2"><font class='base'>$Lang::tr{'dns desc'}<br /><img src="/images/dns_link.png" border="0" align="absmiddle"/><a href="http://wiki.ipfire.org/$Lang::tr{'lang'}/configuration/dns_list" target="_blank">$Lang::tr{'dns list'}</a></font></td>
+    <td colspan="2"><font class='base'>$Lang::tr{'dns desc'}<br /><img src="/images/dns_link.png" border="0" align="absmiddle"/><a href="http://wiki.ipfire.org/en/dns/public-servers" target="_blank">$Lang::tr{'dns list'}</a></font></td>
   </tr>
   <tr>
     <td colspan="2">&nbsp;</td>