Syntax Error in Updates

I made a site using Savona theme on wordpress for a few months. It has been second time that after updates my site does open and gives a fatal error.There is the error is double declaration of certain function. The error is:

Fatal error: Cannot redeclare savona_true_false() (previously declared in /home3/waferswi/public_html/wp-content/themes/savona/inc/customizer/dynamic-css.php:13) in /home3/waferswi/public_html/wp-content/themes/savona/inc/customizer/dynamic-css.php on line 13

Any lead on this?

The page I need help with: [log in to see the link]