Audio thumbnail disabling does not work
Background info:
- OS: Xubuntu 18.04.
- Tested versions: Flatpak, AppImage, Snap - 19.12.3.
- Does not affect versions prior to refactoring.
When unticking Settings->Configure Kdenlive->Timeline->Thumbnails->Audio, Project Bin will create audio thumbnails regardless of the setting.
Steps to reproduce: Untick Settings->Configure Kdenlive->Timeline->Thumbnails->Audio, then import some videos with audio. Project bin starts to create jobs.