Improve certificates import (again)

We noticed at the install party that the question about the certificates could be improved. As a reminder, we first ask the user if they would like to import their certificates from a directory. If they say no, they are invited to copy/paste the content of their certificates.

The question is how could we improve this? Is the copy/paste option still required? We could just explain to the user how to download their certificates (by following this guide, or from an existing cube (reinstall))…

We could also explain what the script will look for. Basically, the script is looking for user.crt / client.crt, user.key / client.key and ca.crt / server-ca.crt, as they are the default name on the cube and in the guide.