Update CMakeLists.txt

OpenSSL embeds client certificate into ticket which might grow beyond
single QUIC packet limitation.  Technically, it is impossible for
OpenSSL based server and client to do resumption with client
certificate for now because QUIC draft mandates that the client
initial must be fit into a single Initial packet.

Embed ngtcp2_transport_params into ngtcp2_settings directly to avoid
conversion.

Original connection ID can now be specified directly to
ngtcp2_transport_params and can be passed to ngtcp2_conn_server_new
via ngtcp2_settings.  As a result, ngtcp2_conn_set_retry_ocid was
removed.

This commit removes the comment for a chunk argument for
ngtcp2_idtr_init as it does not seem to be relative to this function
declaration.