Upstream: duplicate headers ignored or properly linked. Most of the known duplicate upstream response headers are now ignored with a warning. If syntax permits multiple headers, these are now properly linked to the lists, notably Vary and WWW-Authenticate. This makes it possible to further handle such lists where it makes sense.

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


cat << END >> $NGX_AUTO_CONFIG_H

#ifndef $have
#define $have  1
#endif

END