Added variables support to server_tokens. It can now be set to "off" conditionally, e.g. using the map directive. An empty value will disable the emission of the Server: header and the signature in error messages generated by nginx. Any other value is treated as "on", meaning that full nginx version is emitted in the Server: header and error messages generated by nginx.

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


cat << END >> $NGX_AUTO_HEADERS_H

#ifndef $have
#define $have  1
#endif

END