Archimer fails to return document meta-data

I just noticed that the Ifremer Archimer API fails to return one document meta-data.
Hopefully this is temporary.
I will contact them to raise the issue.

ps: I found about this because a design error in CI tests whereby I thought to use the mocked server while I didn't.

So this issue also raises the fact that test_related.m / Test_ArgoDocs is not using the mocked server.

I disabled this test temporarily.

To reproduce the error, send the following request:
```bash
curl -d '{"fields": [], "fileType": "TXT", "listId": [35385], "ldapList": [], "exportAllAvailableFields": "true"}' -H "Content-Type: application/json" -X POST https://archimer.ifremer.fr/api/download-metadata
```
it should return the record data. It does not at this time.