Panic when use-server-name-directories is false

[jamesnvc]

Hello, thanks for this handy tool & your great write-up of your ereader setup; it pushed me over the edge to buy a Libra 2.

It seems that on a fresh install, using using a Settings.toml with the same setup as the sample, changing the server to point to mine and changing use-server-name-directories to false, I get an error when trying to sync:

thread 'main' panicked at src/main.rs:419:65:
called `Result::unwrap()` on an `Err` value: Os { code: 2, kind: NotFound, message: "No such file or directory" }

When changing use-server-name-directories to true, syncing works as expected.

[videah]

I'll check this out in a bit!