Upstream: fixed tcp_nopush with gRPC. With gRPC it is possible that a request sending is blocked due to flow control. Moreover, further sending might be only allowed once the backend sees all the data we've already sent. With such a backend it is required to clear the TCP_NOPUSH socket option to make sure all the data we've sent are actually delivered to the backend. As such, we now clear TCP_NOPUSH in ngx_http_upstream_send_request() also on NGX_AGAIN if c->write->ready is set. This fixes a test (which waits for all the 64k bytes as per initial window before allowing more bytes) with sendfile enabled when the body was written to a file in a different context.

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;