Second attempt with RealSense D435i

No problems* with the D435i anymore.

After talking with Arnoud, it seemed like the sensor should have worked with realsense-viewer. He showed in his labbook that it works with realsense-viewer v2.17.0 on Ubuntu 18.04.

At home, I saw that I use realsense-viewer v2.18.0 on Ubuntu 16.04. It turned out that after an update on those packages through apt-get, it all works. The Linux kernel was also updated, from 4.15.0-43 to 4.15.0-45.