Fix “Illegal string offset ‘notice'”

Currently the plugin creates a log in our system:

PHP Warning: Illegal string offset 'notice' in /var/www/html/wp-content/plugins/side-cart-woocommerce/public/class-xoo-wsc-cart-data.php on line 117

This can be fixed by replacing

wc_print_notice( $value['notice'], 'error' );

through

wc_print_notice( $value, 'error' );