Specifying 'protocols' (Sec-WebSocket-Protocol header) causes connection to close.

[JaxBrachetti]

Issue: When specifying 'protocols' in WebSocketChannel.connect(..), the connection is closed and a vague stack-trace is outputted.
This is occurring for me when using the Web implementation.

Example:

_channel = WebSocketChannel.connect(Uri.parse(wsUrl), protocols: {
        'MQTT' 
});

Causes a js runtime error:

dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/errors.dart 297:3  throw_

dart-sdk/lib/_internal/js_dev_runtime/patch/async_patch.dart 84:54           runBody
dart-sdk/lib/_internal/js_dev_runtime/patch/async_patch.dart 127:5           _async
dart-sdk/lib/async/future_impl.dart 162:18                                   handleValue
dart-sdk/lib/async/future_impl.dart 838:44                                   handleValueCallback
dart-sdk/lib/async/future_impl.dart 867:13                                   _propagateToListeners
dart-sdk/lib/async/future_impl.dart 643:5                                    [_completeWithValue]
dart-sdk/lib/async/future_impl.dart 713:7                                    callback
dart-sdk/lib/async/schedule_microtask.dart 40:11                             _microtaskLoop
dart-sdk/lib/async/schedule_microtask.dart 49:5                              _startMicrotaskLoop
dart-sdk/lib/_internal/js_dev_runtime/patch/async_patch.dart 181:7           <fn>
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/errors.dart 330:10  createErrorWithStack
dart-sdk/lib/_internal/js_dev_runtime/patch/core_patch.dart 337:28            _throw
dart-sdk/lib/core/errors.dart 120:5                                           throwWithStackTrace
dart-sdk/lib/async/zone.dart 1386:11                                          callback
dart-sdk/lib/async/schedule_microtask.dart 40:11                              _microtaskLoop
dart-sdk/lib/async/schedule_microtask.dart 49:5                               _startMicrotaskLoop
dart-sdk/lib/_internal/js_dev_runtime/patch/async_patch.dart 181:7            <fn>

Potentially something to do with?:

web_socket_channel/lib/html.dart

Line 80 in 3db86bc

protocols?.map((e) => e.toJS).toList().toJS ?? JSArray(),