Invalid data in projects table

These problems were found in the database of our customers and GitLab.com as well

There are a few types of errors:

ActiveRecord::RecordInvalid: Validation failed: Name can contain only letters, digits, '_', '.', dash and space. It must start with letter, digit or '_'. 

and

ActiveRecord::RecordInvalid: Validation failed: Name has already been taken, Path has already been taken

And the same validation error for import_url

We see this whenever we try to update a record, even if our change is not related. /cc @dzaporozhets @DouweM