Table headers not visible when viewing the submission

When submitting form values in Table Element and then viewing the submission, the table headers are not visible.

This is because at the function _webform_table_element_alter_submission() the headers are defined like:

$submission->data[$parent['cid']]['value'] = array('headers' => $headers, 'rows' => $rows);

even though those should be in format:

$submission->data[$parent['cid']]['value'] = array('header' => $headers, 'rows' => $rows);

(See theme_table())

Patch attached.