FsDiscoverer: Don't insert files in a transaction.
FsDiscoverer: Don't insert files in a transaction.

The coming changes will insert tasks & their item in a transaction
though, but this way we are reducing the likeliness of the database
being hardly readable when a scan is in progress

chouquette/medialibrary,chouquette/medialibrary,chouquette/medialibrary,chouquette/medialibrary