fdbcli --debug-tls will print out the same certificate twice

I went through like 5 different iterations of how to load and print a certificate chain, and apparently I still got it wrong.

```
$ fdbcli -C ../fdb.cluster --debug-tls
TLS Configuration:
...

Certificate:
Data:
Version: 3 (0x2)
Serial Number: 3246816641601864293 (0x2d0f02887d818265)

Certificate:
Data:
Version: 3 (0x2)
Serial Number: 3246816641601864293 (0x2d0f02887d818265)
```

So it's possible that the "print the rest of the chain" code is all that's needed, and I was wrong that the user-set end certificate needs to be printed separately?

Start by reproducing the issue with `fdbcli -C ../fdb.cluster --debug-tls` and inspect the TLS certificate-chain printing entry point. Confirm why the same certificate is emitted twice, determine the intended chain output, and verify that the command prints each certificate once.

Written by the indexing model from the issue text.