Hotfix: nclocator may be invalid in database

Problem

The BigBlueButton frontend B3Desk permits to show documents in a room and they can be retrieves from a nextcloud.

It need access to the user nclocator throught laboite API but the returned value may not have the protocol scheme https:// and must be handled by the B3Desk.

In the future, other clients may have the same issue.

Proposal

• Even if it's always a good practice to validate returned data in the client, laboite API cloud parse the nclocator when retrieved for the database and append the scheme https:// if it's missing
• We cloud provide a way to fix the database values

/cc @benoit.piedallu