Apply server configuration as soon as host is known. Previously, this was done only after the whole request header was parsed, and if an error occurred earlier then the request was processed in the default server (or server chosen by SNI), while r->headers_in.server might be set to the value from the Host: header or host from request line. r->headers_in.server is in turn used for $host variable and in HTTP redirects if "server_name_in_redirect" is disabled. Without the change, configurations that rely on this during error handling are potentially unsafe if SNI is used. This change also allows to use server specific settings of "underscores_in_headers", "ignore_invalid_headers", and "large_client_header_buffers" directives for HTTP requests and HTTPS requests without SNI.

uwsgi_param  QUERY_STRING       $query_string;
uwsgi_param  REQUEST_METHOD     $request_method;
uwsgi_param  CONTENT_TYPE       $content_type;
uwsgi_param  CONTENT_LENGTH     $content_length;

uwsgi_param  REQUEST_URI        $request_uri;
uwsgi_param  PATH_INFO          $document_uri;
uwsgi_param  DOCUMENT_ROOT      $document_root;
uwsgi_param  SERVER_PROTOCOL    $server_protocol;
uwsgi_param  HTTPS              $https if_not_empty;

uwsgi_param  REMOTE_ADDR        $remote_addr;
uwsgi_param  REMOTE_PORT        $remote_port;
uwsgi_param  SERVER_PORT        $server_port;
uwsgi_param  SERVER_NAME        $server_name;