Do not blindly reset secrets/tokens if script gets re-executed.

[dzatoah]

This is a known bug. If the script gets re-executed, every token/secret for every Nextcloud domain will be re-generated. This leads to the inconvenience, that you'll have to re-enter the tokens/secrets into the Nextcloud settings everytime the script gets re-executed.

This can be circumvented by adding a new dialog, which asks if and which secrets/tokens should be renewed.