wp-config file location

I am using Multi-Domains and Domain Mapping. After copying the sunrise.php file to wp-content folder I get this message:

Please copy the content of sunrise.php into /var/www/html/mitchell1/wp-content/sunrise.php and uncomment the SUNRISE setting in the /var/www/html/mitchell1/wp-content/wp-config.php file.

My config file is found at /var/www/html/mitchell1/

How do I uncomment the sunrise setting with differing config locations?