Error after installing S3 optimizer

This is the error I’m seeing after activating the plugin (S3 image optimizer):

Fatal error: Cannot redeclare class EDD_SL_Plugin_Updater in /home/spectoos/public_html/wp-content/plugins/s3-image-optimizer/EDD_SL_Plugin_Updater.php on line 15

Thanks,
Guy.

https://ww.wp.xz.cn/plugins/ewww-image-optimizer/