nurse command is not working as should

I think the following cases is missing by the coffee nurse command

```
➜ ~ coffee --network testnet remote add folgore-git https://github.com/coffee-tools/folgore.git
✗ Fetch remote from https://github.com/coffee-tools/folgore.git error: Error while add remote: code: 1, msg: '/home/vincent/.coffee/repositories/folgore-git' exists and is not an empty directory
✗ Error: code: 1, msg: '/home/vincent/.coffee/repositories/folgore-git' exists and is not an empty directory
➜ ~ coffee --network testnet nurse
✓ Coffee configuration is not corrupt! No need to run coffee nurse
```

cc @tareknaser

I think we should trust our database, and if in the database there is nothing we wipe everything there is on disk. What do you think?