Fixed XML dump
bug #9330 [2.4][Config] Fixed namespace when dumping reference (WouterJ)

This PR was merged into the master branch.

Discussion
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[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.

Commits
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2b0b355 Fixed XML dump