message: clearer comment on doubleparse of cli flags
diff: @@ -748,9 +748,10 @@ impl Config {
  if let Some(unstable_flags) = self.get::<Option<CliUnstable>>("unstable")? {
  self.unstable_flags = unstable_flags;
  }
  - // NB. It sucks to parse these twice, but doing it again here
  + // NB. It's not ideal to parse these twice, but doing it again here
  // allows the CLI to override config files for both enabling
  - // and disabling.
  + // and disabling, and doing it up top allows CLI Zflags to
  + // control config parsing behavior.
  self.unstable_flags.parse(unstable_flags)?;
  }
  