gRPC: RST_STREAM(NO_ERROR) handling (ticket #1792). As per https://tools.ietf.org/html/rfc7540#section-8.1, : A server can send a complete response prior to the client : sending an entire request if the response does not depend on : any portion of the request that has not been sent and : received. When this is true, a server MAY request that the : client abort transmission of a request without error by : sending a RST_STREAM with an error code of NO_ERROR after : sending a complete response (i.e., a frame with the : END_STREAM flag). Clients MUST NOT discard responses as a : result of receiving such a RST_STREAM, though clients can : always discard responses at their discretion for other : reasons. Previously, RST_STREAM(NO_ERROR) received from upstream after a frame with the END_STREAM flag was incorrectly treated as an error. Now, a single RST_STREAM(NO_ERROR) is properly handled. This fixes problems observed with modern grpc-c [1], as well as with the Go gRPC module. [1] https://github.com/grpc/grpc/pull/1661

scgi_param  REQUEST_METHOD     $request_method;
scgi_param  REQUEST_URI        $request_uri;
scgi_param  QUERY_STRING       $query_string;
scgi_param  CONTENT_TYPE       $content_type;

scgi_param  DOCUMENT_URI       $document_uri;
scgi_param  DOCUMENT_ROOT      $document_root;
scgi_param  SCGI               1;
scgi_param  SERVER_PROTOCOL    $server_protocol;
scgi_param  REQUEST_SCHEME     $scheme;
scgi_param  HTTPS              $https if_not_empty;

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