Executing `web_renderer.draw()` results in dead kernel in Jupyter notebook (Docker)

**Describe the bug**
Kernel dies when trying to display something with `web_renderer.draw()` inside a Jupyter notebook in a Docker container.

**To Reproduce**
Steps to reproduce the behavior:
1. Install Open3D from source following [these instructions](http://www.open3d.org/docs/release/tutorial/visualization/web_visualizer.html#build-jupyter-package-from-source) and passing `BUILD_JUPYTER_EXTENSION=ON` and `BUILD_WEBRTC=ON` flags to `cmake`.
2. Run [this sample code](https://github.com/intel-isl/Open3D/blob/master/examples/python/visualization/jupyter_visualization.ipynb) in a Jupyter notebook.

**Expected behavior**
The notebook cell should display a cube.

**Screenshots**

**Environment (please complete the following information):**

- Operating system: Manjaro Linux x86_64 with 5.13.8-1-MANJARO kernel (host), Ubuntu 18.04.5 LTS (container)
- Python version: Python 3.8
- Open3D version: 0.13.0+d92de2bff
- Is this remote workstation?: yes or no
- How did you install Open3D?: build from source
- Compiler version (if built from source): gcc 7.5

**Additional context**
I tested locally with Open3D 0.13.0.0 version installed via pip and the kernel does not die, but the cube is not displayed either.