Fix "Error ‘[Errno 17] File exists’ processing ssl/ssl_certificate.pem" When Restoring Mail-in-a-Box

When restoring a blank Mail-in-a-Box, you may get this error:

Error ‘[Errno 17] File exists’ processing ssl/ssl_certificate.pem

Solution to fix the problem is to run this command before running the restore:

rm -rf /home/user-data/ssl/*

After deleting this directory, the restore should run without problems.