[nginx.tmpl] Cors add_header always

[talset]

According http://nginx.org/en/docs/http/ngx_http_headers_module.html there's an option named always that always returns the header field regardless of the response code.

It is useful particularly on cors headers.

Do you think it worst it to add a new annotation like annotationCorsAlways in order to define a variable like $cors.CorsAlways = "" or "always"

Example :

add_header 'Access-Control-Allow-Origin' '{{ $cors.CorsAllowOrigin }} {{ $cors.CorsAlways }}';