[DDS] Can't access debug web app on localhost but works on 127.0.0.1

## Steps to reproduce:
```
# create a web project
dart create -t web myapp
cd myapp
dart pub global activate webdev
```
start debug daemon (since that's what vscode seems to be doing)
```
webdev daemon web:8080
```

This starts the web app at `127.0.0.1:8080`

If I change the browser address to `localhost:8080` it crashes the daemon with below error
```
[{"event":"daemon.log","params":{"log":"[INFO] Received request for entrypoint at http://localhost:8082/main.dart.bootstrap.js"}}]
[{"event":"daemon.log","params":{"log":"[INFO] Loading debug metadata..."}}]
[{"event":"daemon.log","params":{"log":"[INFO] Loaded debug metadata (sound null safety)"}}]
[{"event":"daemon.log","params":{"log":"[INFO] Injected debugging metadata for entrypoint at http://localhost:8082/main.dart.bootstrap.js"}}]
[{"event":"daemon.log","params":{"log":"[INFO] Initializing expression compiler for main.dart.bootstrap.js with sound null safety: true"}}]
[{"event":"daemon.log","params":{"log":"[INFO] Updating dependencies..."}}]
Unhandled exception:
WebSocketException: Connection to 'http://127.0.0.1:62716/v5_zz3h5jg0=/ws#' was not upgraded to websocket
#0 _WebSocketImpl.connect (dart:_http/websocket_impl.dart:1011:41)
dart-lang/webdev#1 WebSocket.connect (dart:_http/websocket.dart:320:22)
dart-lang/webdev#2 new IOWebSocketChannel.connect (package:web_socket_channel/io.dart:80:28)
dart-lang/webdev#3 connect (package:web_socket_channel/src/_connect_io.dart:15:24)
dart-lang/webdev#4 new WebSocketChannel.connect (package:web_socket_channel/src/channel.dart:115:16)
dart-lang/webdev#5 _defaultWebSocketBuilder (package:dds/src/dds_impl.dart:51:27)
dart-lang/webdev#6 DartDevelopmentServiceImpl.startService (package:dds/src/dds_impl.dart:78:40)
dart-lang/webdev#7 DartDevelopmentService.startDartDevelopmentService (package:dds/dds.dart:97:19)

dart-lang/webdev#8 DebugService.startDartDevelopmentService (package:dwds/src/services/debug_service.dart:154:12)

dart-lang/webdev#9 DevHandler._createAppDebugServices (package:dwds/src/handlers/dev_handler.dart:466:7)

dart-lang/webdev#10 DevHandler.loadAppServices (package:dwds/src/handlers/dev_handler.dart:241:21)

dart-lang/webdev#11 Dwds.debugConnection (package:dwds/dart_web_debug_service.dart:61:30)

dart-lang/webdev#12 AppDomain._handleAppConnections (package:webdev/src/daemon/app_domain.dart:62:29)

```

ps, I am on mac. Not sure if this is related to dart-lang/webdev#233 and dart-lang/webdev#402 since they are able to access on localhost but not on 127.0.0.1 but it's opposite in my case.

Also here's my `/etc/hosts`
```
127.0.0.1 localhost
255.255.255.255 broadcasthost
::1 localhost
```