Update wrong INI section for malware scan in the docs

[tubiz]

I noticed that the wrong INI section for malware scan is used in the docs.

I tested [SCAN], [MALWARE-SCAN], and [MALWARE_SCAN] to be sure and the correct value should be [MALWARE_SCAN]

[akenion]

Thanks for the PR. MALWARE_SCAN is the correct INI section. Since this is just a documentation change and not a code change, I'm just going to merge it without creating a new release.