perl: uncomment the json entrries in the rootfile

perl: uncomment the json entrries in the rootfile

- Back in Sept 2024 I supplied a patch to remove certain perl modules as they were now
   available in the core perl package.
- The perl-json was one of these modules but unfortunately I missed to uncomment the json
   entries in the perl rootfile so they have been unavailable to samba since then.
- This patch corrects that situation.

Suggested-by: ummeegge <ummeegge@ipfire.org>
Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>