QUIC: ngx_quic_buffer_t use-after-free protection. Previously the last chain field of ngx_quic_buffer_t could still reference freed chains and buffers after calling ngx_quic_free_buffer(). While normally an ngx_quic_buffer_t object should not be used after freeing, resetting last_chain field would prevent a potential use-after-free.

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


cat << END >> $NGX_AUTO_HEADERS_H

#ifndef $have
#define $have  1
#endif

END