Update antivirus_configuration.rst

[userofgithub023897]

The former command didn`t work.

occ config:app:set files_antivirus av_background_scan –-value="off"

It caused the error:

Too many arguments to "config:app:set" command, expected arguments "app" "name".
``

### ☑️ Resolves

The new command worked without any problems.

occ config:app:set files_antivirus av_background_scan --value="yes"

The message shows the successful execution of the command:

Config value av_background_scan for app files_antivirus set to yes

### 🖼️ Screenshots

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