send a http status code 204 instead of 202 on buffered write

send a http status code 204 since 202 is not compliant with the write API endpoint of influxdb

relay/retry.go

@@ -84,9 +84,9 @@ func (r *retryBuffer) post(buf []byte, query string, auth string, endpoint strin
 
 	// We do not wait for the WaitGroup because we don't want
 	// to leave the connection open
-	// The client will receive a 202 which closes the connection and
+	// The client will receive a 204 which closes the connection and
 	// invites him to send further requests
-	return &responseData{StatusCode: http.StatusAccepted}, err
+	return &responseData{StatusCode: http.StatusNoContent}, err
 }
 
 func (r *retryBuffer) run() {