Plugin not activating: Error upon activating!

I’m having an issue activating the plugin. I’m getting this error upon activating.

Plugin could not be activated because it triggered a fatal error.
Parse error: syntax error, unexpected T_STRING in /home/esteemst/public_html/wp-content/plugins/wp-optimize-by-xtraffic/wp-optimize-by-xtraffic.php on line 81

I hope you can help me thanks!
http://www.esteemstudio.com.au/

Best regards.

https://wordpress.org/plugins/wp-optimize-by-xtraffic/