Unused variables

[romaingugert]

You can use PHP Mess dector (https://phpmd.org/) to detects when a variable is not used.

> ./phpmd.phar ./ text unusedcode 
multisite-clone-duplicator-develop/include/admin.php:100	Avoid unused local variables such as '$current_site'.
multisite-clone-duplicator-develop/lib/data.php:39	Avoid unused local variables such as '$to_site_prefix_length'.
multisite-clone-duplicator-develop/lib/data.php:43	Avoid unused local variables such as '$option_value'.
multisite-clone-duplicator-develop/lib/data.php:137	Avoid unused local variables such as '$col'.
multisite-clone-duplicator-develop/lib/data.php:215	Avoid unused local variables such as '$result'.
multisite-clone-duplicator-develop/lib/data.php:257	Avoid unused local variables such as '$v'.
multisite-clone-duplicator-develop/lib/duplicate.php:149	Avoid unused local variables such as '$to_site_prefix_length'.
multisite-clone-duplicator-develop/lib/functions.php:146	Avoid unused parameters such as '$locale'.
multisite-clone-duplicator-develop/wp-cli/wp-cli-site-duplicate-subcommand.php:53	Avoid unused parameters such as '$_'.
multisite-clone-duplicator-develop/wp-cli/wp-cli-site-duplicate-subcommand.php:177	Avoid unused local variables such as '$user'.