Demo cellphone is broken

Steps to reproduce

1. Install x86_64 gcc desktop from qt-enterprise-linux-x64-5.12.0-beta2_884.run
2. Open example "Interactive Mobile Phone"
3. Run

Expected result:

• You see a demo with rotating 3d cellphone

Actual result:

• qrc:/three.js:2075: TypeError: Cannot read property 'x' of undefined
• Rotating cellphone is not visible, background and buttons are drawn

Also broken on 5.12.0-beta 2 / QNX / x86_64,  Ubuntu 16.04.4 LTS, gcc 5.4.0

 see https://bugreports.qt.io/browse/QTBUG-71346