Run listing contains wrong key

The XML returned by the list runs function contains a field uploader, but instead of the name of the uploader it contains the uploader ID.

Reproduce:

https://test.openml.org/api/v1/xml/run/list/limit/1/task/1

Output

<oml:runs>
  <oml:run>
    <oml:run_id>8151</oml:run_id>
    <oml:task_id>1</oml:task_id>
    <oml:task_type_id>1</oml:task_type_id>
    <oml:setup_id>6950</oml:setup_id>
    <oml:flow_id>24682</oml:flow_id>
    <oml:uploader>1</oml:uploader>
    <oml:upload_time>2019-03-22 14:15:53</oml:upload_time>
    <oml:error_message/>
    <oml:run_details/>
  </oml:run>
</oml:runs>

Expected Output

<oml:runs>
  <oml:run>
    <oml:run_id>8151</oml:run_id>
    <oml:task_id>1</oml:task_id>
    <oml:task_type_id>1</oml:task_type_id>
    <oml:setup_id>6950</oml:setup_id>
    <oml:flow_id>24682</oml:flow_id>
    <oml:uploader_id>1</oml:uploader_id>
    <oml:upload_time>2019-03-22 14:15:53</oml:upload_time>
    <oml:error_message/>
    <oml:run_details/>
  </oml:run>
</oml:runs>

Start by tracing the run listing implementation behind /api/v1/xml/run/list/limit/1/task/1 and inspect how the uploader field is serialized. Done means the response uses uploader_id with the reported ID, matching the expected XML output; verify the endpoint response afterward.