message: [BrowserCodeReader] Fix isVideoPlaying check in tryPlayVideo.
  This should prevent the function from returning early in any case the
  video isn't actually `playing`.
  As a side effect this removes most of the `IndexSizeError` based
  `DomExceptions` which mostly appear in firefox even if it doesn't
  remove the actual error cause.
  .. refs zxing-js/library#156
diff: @@ -324,7 +324,7 @@ export class BrowserCodeReader {
  */
  async tryPlayVideo(videoElement: HTMLVideoElement): Promise<void> {
  - if (!this.isVideoPLaying(videoElement)) {
  + if (this.isVideoPLaying(videoElement)) {
  console.warn('Trying yo play video that is already playing.');
  return;
  }
  