daemon/tls: use GNUTLS_NO_TICKETS_TLS12

Closes #742 (closed)

daemon/bindings/net_tlssrv.rst

@@ -121,10 +121,10 @@ by a trusted CA. This is done using function :c:func:`net.tls()`.
    `secret leaks eventually <pfs_>`_.
 
    .. warning:: **Setting the secret is probably too risky with TLS <= 1.2 and
-      GnuTLS < 3.6.5**. GnuTLS 3.6.5 adds an option to disable resumption via
+      GnuTLS < 3.7.5**. GnuTLS 3.7.5 adds an option to disable resumption via
       tickets for TLS <= 1.2, enabling them only for protocols that do guarantee
       `PFS <pfs_>`_. Knot Resolver makes use of this new option when linked
-      against GnuTLS >= 3.6.5.
+      against GnuTLS >= 3.7.5.
 
 .. function:: net.tls_sticket_secret_file([string with path to a file containing pre-shared secret])