NXQL should be able to query metadata set with default values

If a value for a metadata is set from the table default value, this value is shown in the interface but cannot be queried by NXQL.
To reproduce:

• create a string metadata with a default value (for instance toto for my:data) and assign it to a doc type.
• deploy and create a document that has this metadata.
• You can see in the UI that the metadata is toto (OK)
• But with NXQL, you cannot find the doc with "select * from Document where my:data='toto' but it should.

It's seems OK that existing documents are not updated but new docs should have the value