Repository: atuinsh/atuin (language: rust)

Issue:
[Bug]: Server - failed to deserialize: missing field `mail`
### What did you expect to happen?

@ellie, @tessus

The field `mail` from https://github.com/atuinsh/atuin/pull/2190 was not generated automatically in `server.toml`.
And I didn't find anything in https://docs.atuin.sh/self-hosting/server-setup/#configuration.
Is there some documentation what is needed?

### What happened?

When I run the latest docker image from https://github.com/atuinsh/atuin/pkgs/container/atuin (6e15286-amd64) for the first time, I get a:

     failed to deserialize: missing field `mail`


### Atuin doctor output

```yaml
atuin-server-1  | Error: could not load server settings
atuin-server-1  |
atuin-server-1  | Caused by:
atuin-server-1  |     failed to deserialize: missing field `mail`
atuin-server-1  |
atuin-server-1  | Location:
atuin-server-1  |     /app/crates/atuin-server/src/settings.rs:133:26
```


### Code of Conduct

- [X] I agree to follow this project's Code of Conduct


Discussion / hints:
I am using the same config as in the guide I wrote on the forum. My server is atuin 18.3.0.

It could be possible that there's been a regression since then. I haven't tried git master server-side. I believe the issue is here: 

https://github.com/atuinsh/atuin/blob/main/crates/atuin-server/src/settings.rs#L68

I believe it should be `pub mail: Option<Mail>,` instead.
For now, I got over the error with:

```toml
[mail]
enable = false
```
Yep, setting a default value in the builder should work too (after line 109):

```rust
    .set_default("mail.enable", false)?
```
By the way, is this feature turned on on the official server? I registered an account today and never got an email. 
Idk, this is a question for ellie...

Fix patch:
diff --git a/crates/atuin-server/src/settings.rs b/crates/atuin-server/src/settings.rs
index db26051162f..63763b2c2b3 100644
--- a/crates/atuin-server/src/settings.rs
+++ b/crates/atuin-server/src/settings.rs
@@ -104,6 +104,7 @@ impl<DbSettings: DeserializeOwned> Settings<DbSettings> {
             .set_default("metrics.enable", false)?
             .set_default("metrics.host", "127.0.0.1")?
             .set_default("metrics.port", 9001)?
+            .set_default("mail.enable", false)?
             .set_default("tls.enable", false)?
             .set_default("tls.cert_path", "")?
             .set_default("tls.pkey_path", "")?


Test patch: