Smush Pro Multisite Activation 500 Error

Whenever I try to network activate, I get this 500 error:

07-Feb-2017 01:55:04 UTC] PHP Fatal error:  Cannot redeclare i18n() (previously declared in /home/denverpr/public_html/wp-content/plugins/wp-smushit/wp-smush.php:278) in /home/denverpr/public_html/wp-content/plugins/wp-smush-pro/wp-smush.php on line 274