FIx importer when md is already validated

[f-necas]

In 4.2.8 (georchestra 24) we couldn't update with importer a matadata which has already been validated.

Steps to reproduce :
import a metadata and validate it.
Download xml and change title
Re-import with override
Title hasn't changed.

geOrchestra/geonetwork checklist

• PR only involves cherry-picked commits from upstream.
• PR contains custom code which will soon be available in an upstream release and can be overriden => 4.4.4
• PR contains custom geOrchestra code, which need to be verified during future migrations.
  • I have properly filled the migration-dev-guide.md file.

[pmauduit]

upstream fix: geonetwork/core-geonetwork@3444440

[pmauduit]

Not a JPA expert, but looks good ; as already applied to upstream, I guess we can go with it.

[MaelREBOUX]

I can confirm that it works.