This change better resembles the output generated by `Snapshot.String()`,
which includes both username and hostname.
Closes#4506
Before:
```
$ restic copy --from-repo /srv/restic-repo
repository 3666882b opened (version 2, compression level auto)
repository 0085c387 opened (version 2, compression level auto)
created new cache in /home/mike/.cache/restic
[0:00] 100.00% 1 / 1 index files loaded
[0:00] 0 index files loaded
snapshot 32b39a20 of [/home/mike/data] at 2023-10-21 16:01:13.979948154 -0300 -03)
copy started, this may take a while...
[0:00] 100.00% 1 / 1 packs copied
snapshot 10331fdd saved
```
After:
```
$ restic copy --from-repo /srv/restic-repo
repository 3666882b opened (version 2, compression level auto)
repository 0085c387 opened (version 2, compression level auto)
[0:00] 100.00% 1 / 1 index files loaded
[0:00] 0 index files loaded
snapshot 32b39a20 of [/home/mike/data] at 2023-10-21 16:01:13.979948154 -0300 -03 by mike@desktop)
copy started, this may take a while...
[0:00] 100.00% 1 / 1 packs copied
snapshot a67bd1ee saved
```
