Preserve original DCID and unbreak parsing 0-RTT packets. As per QUIC transport, the first flight of 0-RTT packets obviously uses same Destination and Source Connection ID values as the client's first Initial. The fix is to match 0-RTT against original DCID after it has been switched.

# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


cat << END >> $NGX_AUTO_CONFIG_H

#ifndef $have
#define $have  $value
#endif

END