App server is not restarted after webpack rebuilding after some error

Log:

```
[1] [piping] File src\redux\modules\system-settings.js has changed, reloading.
[1] node.js:765
[1] throw errnoException(err, 'kill');
[1] ^
[1]
[1] Error: kill ESRCH
[1] at exports._errnoException (util.js:849:11)
[1] at process.kill (node.js:765:15)
[1] at EventEmitter. (c:\Users\Yufan\Documents\Repo\react-redux-universal-hot-example\node_modules\piping\lib\piping.js:87:19)
[1] at emitTwo (events.js:87:13)
[1] at EventEmitter.emit (events.js:172:7)
[1] at EventEmitter. (c:\Users\Yufan\Documents\Repo\react-redux-universal-hot-example\node_modules\piping\node_modules\chokidar\index.js:173:15)
[1] at EventEmitter.FSWatcher._emit (c:\Users\Yufan\Documents\Repo\react-redux-universal-hot-example\node_modules\piping\node_modules\chokidar\index.js:203:5)
[1] at EventEmitter. (c:\Users\Yufan\Documents\Repo\react-redux-universal-hot-example\node_modules\piping\node_modules\chokidar\lib\nodefs-handler.js:263:16)
[1] at FSReqWrap.oncomplete (fs.js:82:15)
[1] npm run start-dev exited with code 0
--> Sending SIGTERM to other processes..
```

Afterwards the app server will not be restarted until a manual reboot, while the API server and the watch server stays on. At manual process kill log shows:

```
[2] npm run start-dev-api exited with code null
[0] npm run watch-client exited with code null
```