修改nginx的http响应头server字段

修改src/http/ngx_http_header_filter_module.c

找到下面两行：
static char ngx_http_server_string[] = "Server: nginx" CRLF;
static char ngx_http_server_full_string[] = "Server: " NGINX_VER CRLF;

将其修改为：
static char ngx_http_server_string[] = "Server: nginx" CRLF;
static char ngx_http_server_full_string[] = "Server: SWS" CRLF;