message: [fixup] use single-line serde annotations
diff: @@ -334,9 +334,7 @@ impl Features {
  ///
  /// If you have any trouble with this, please let us know!
  #[derive(Default, Debug, Deserialize)]
  -#[serde(default)]
  -#[serde(deny_unknown_fields)]
  -#[serde(rename_all="kebab-case")]
  +#[serde(default, deny_unknown_fields, rename_all="kebab-case")]
  pub struct CliUnstable {
  pub print_im_a_teapot: bool,
  pub unstable_options: bool,
  