Upstream: fixed u->conf->preserve_output (ticket #1519). Previously, ngx_http_upstream_process_header() might be called after we've finished reading response headers and switched to a different read event handler, leading to errors with gRPC proxying. Additionally, the u->conf->read_timeout timer might be re-armed during reading response headers (while this is expected to be a single timeout on reading the whole response header).

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


cat << END >> $NGX_AUTO_CONFIG_H

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

END