Changes on webpack.config.js does not trigger webpack rebuild

When you change only the **webpack.config.js** e.g. adding a new item to the **appComponents** collection:
```javascript
    const appComponents = [
        "tns-core-modules/ui/frame",
        "tns-core-modules/ui/frame/activity",
        resolve(__dirname, "app/MyNativeScriptActivity"),
    ];
```
 the CLI wouldn't trigger a webpack rebuild and the changes wouldn't be applied.