yarn dev: Error: Must provide a proper URL as target at ProxyServer.<anonymous>

**Describe the bug**
In `yarn dev` mode, opening `http://localhost:8010/` run into

```
Error: Must provide a proper URL as target
at ProxyServer. (/label-studio/web/node_modules/http-proxy/lib/http-proxy/index.js:69:35)
at HttpProxyMiddleware.middleware (/label-studio/web/node_modules/http-proxy-middleware/dist/http-proxy-middleware.js:22:32)
at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
```

**To Reproduce**
Steps to reproduce the behavior:
1. Install for local development

Download latest dev branch. Following the READM.md in under `web` folder https://github.com/HumanSignal/label-studio/blob/0f5a47873a24080f74e3edf50cf3cbee96ef98a0/web/README.md#installation-instructions
```
yarn install --frozen-lockfile
```
create the .env (with the same content as .env.development
From the `web` directory: Run `yarn dev` and wait till

```
webpack compiled successfully
```

2. Go to http://localhost:8010
3. The yarn session will show the error msg reported above, and the browser also shows the same error msg.

**Expected behavior**
yarn dev should result in working frontend session, and `http://localhost:8010` should show the label-studio UI

**Environment (please complete the following information):**
- Ubuntu 22.04.1 LTS
- Browser: Chrome
- Label Studio Version origin/develop e4c2721131e1d4b62319b42410d0a8c06ec533fd