Bug#690705: virtualbox-dkms: module not installed/loaded without reinstalling the package

[Vincas Dargis]

Looks like it's still the case on Unstable. Just upgraded linux-image-4.19.0-5-amd64:amd64 4.19.37-4 
and VBox'es failed to start with some NS.. error. Reinstalling -dkms fixes the issue.