scripts/GRMLBASE/94-update-smart-drivedb: switch warning into note since update-smart...

scripts/GRMLBASE/94-update-smart-drivedb: switch warning into note since update-smart-drivedb is deprecated

Quoting NEWS file from smartmontools (6.4+svn4214-1):

|   Previous versions of the smartmontools package included a tool
|   update-smart-drivedb which downloaded updated drive definitions
|   from the smartmontools website and stored them at
|
|       /var/lib/smartmontools/drivedb/drivedb.h
|
|   This tool did not download the definitions in a secure manner and
|   so the feature has been removed in this version.  Future drive DB
|   updates will be propagated via normal Debian package updates,
|   including backports.
|
|   If you already have a drivedb.h file at that location, smartctl
|   will continue to use it.

We could completely drop the package once we're certain that
update-smart-drivedb doesn't exist anymore in all the Debian
releases grml-live is building for, but for the time being
let's keep it and switch the warning into a note.