This is a false positive and it has already been fixed by Avast. Please update your Avast from the previous version which has the issue: 091203-0, to the updated fix: 091203-1. Then update the program itself, from version: 4.8.1356, to the updated version: 4.8.1368. Restart your computer. That should fix it.
This is how to get your Spybot-S&D back, if you have deleted any files with Avast: