Fix cleanup when there isn't an error

[jefft]

My last Mailchimp PR https://github.com/tbar0970/jethro-pmm/pull/984 introduced a bug. The script would break (after successfully syncing) if debug=0 and there weren't any sync errors:

PHP Fatal error:  Uncaught RuntimeException: Directory name must not be empty. in /home/jethro/code/2.34.1/app/scripts/mailchimp_sync.php:351

Fixed by moving the cleanup line into the correct code block.