message: make consistent error message
diff: @@ -64,7 +64,7 @@ impl BuildConfig {
  let cfg = config.build_config()?;
  let requested_kinds = CompileKind::from_requested_targets(config, requested_targets)?;
  if jobs == Some(0) {
  - anyhow::bail!("jobs must not be zero")
  + anyhow::bail!("jobs may not be 0")
  }
  if jobs.is_some() && config.jobserver_from_env().is_some() {
  config.shell().warn(
  