Does not print in Firefox

[cameracker]

Printing does not work in firefox correctly, because the print call needs to be wrapped in a setTimeout call, like so:

setTime(() => {
  iframe.contentWindow.print();
  callback && callback(iframe);
  
  _this.changed = false;
  _this.props.onEnd();
}, 1);

I can prepare a PR if you would like :)

[hanzhangyu]

Thanks, But I have not succeeded in recreating this problem, Can you provide a codepen or an online link? I have tried in the firefox with 66.0.2 and 67.0 (64-bit) version on my window10.