[master] Added a warning about required update of the server code

src/lib/dns/tsig.h

@@ -4,6 +4,10 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
+// IMPORTANT: the server side of this code MUST NOT be used until
+// it was fixed, cf draft-dupont-dnsop-rfc2845bis-00.txt
+// Note that Kea uses only the client side.
+
 #ifndef TSIG_H
 #define TSIG_H 1