message: Don't refer to --config as unstable
diff: @@ -476,14 +476,7 @@ See 'cargo help <command>' for more information on a specific command.\n",
  .arg(flag("frozen", "Require Cargo.lock and cache are up to date").global(true))
  .arg(flag("locked", "Require Cargo.lock is up to date").global(true))
  .arg(flag("offline", "Run without accessing the network").global(true))
  - .arg(
  - multi_opt(
  - "config",
  - "KEY=VALUE",
  - "Override a configuration value (unstable)",
  - )
  - .global(true),
  - )
  + .arg(multi_opt("config", "KEY=VALUE", "Override a configuration value").global(true))
  .arg(
  Arg::new("unstable-features")
  .help("Unstable (nightly-only) flags to Cargo, see 'cargo -Z help' for details")
  