[2.4][Config] Fixed namespace when dumping reference

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

The namespace was given to the wrong function, resulting in wrong namespaes when dumping XML.