message: docs: fix division by zero in progress events example
  If the `event.total` is undefined, this line would have generated a `NaN` due to division by zero. I suppose, that a `0` would be more suitable for this case.
  PR Close
diff: @@ -62,7 +62,7 @@ export class UploaderService {
  case HttpEventType.UploadProgress:
  // Compute and show the % done:
  - const percentDone = Math.round(100 * event.loaded / (event.total ?? 0));
  + const percentDone = event.total ? Math.round(100 * event.loaded / event.total) : 0;
  return `File "${file.name}" is ${percentDone}% uploaded.`;
  case HttpEventType.Response:
  