WebView disappear after pressing home button

[calbee633810]

Steps to reproduce:

1. Open app "Serval Mesh"
2. Click Help
3. Do something in the WebView (e.g., navigate through several urls, scroll down/up, etc.)
4. Press home button and re-enter the app
5. WebView should persist its state, however, it disappears after step 4, making users lose their state.

Screenshot before step 4

Screenshot after step 4

Its very annoying because we have to make efforts to make WebView restore its states. Hope this can be fixed quickly.