dns.cgi: Revert "dns.cgi: Fixes bug#12395 - German umlauts not correctly displayed in remarks"

- This reverts commit 7c6ff5ff12
- That commit removed the cleanhtml command which is not advised, based on feedback from
   Michael Tremer from other patch submissions as it creates a potential security problem.

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

html/cgi-bin/dns.cgi

@@ -141,6 +141,8 @@ if (($cgiparams{'SERVERS'} eq $Lang::tr{'save'}) || ($cgiparams{'SERVERS'} eq $L
 
 	# Go further if there was no error.
 	if ( ! $errormessage) {
+		# Check if a remark has been entered.
+		$cgiparams{'REMARK'} = &Header::cleanhtml($cgiparams{'REMARK'});
 
 		my %dns_servers = ();
 		my $id;