Show label of source field in convert form

When converting nodes, the machine names of fields are sometimes not specific enough. Especially core taxonomy fields like "taxonomy_vocabulary_1" do not tell the user right away its human-readable name. So, in line 265 of node_convert.module I changed

        $form['dest_field_' . $i] = array(
          '#type' => 'select',
          '#options' => $options,
          '#default_value' => $source_field['field_name'],
          '#title' => $source_field['field_name'] . " " . t("should be inserted into"),
        );

to

        $form['dest_field_' . $i] = array(
          '#type' => 'select',
          '#options' => $options,
          '#default_value' => $source_field['field_name'],
          '#title' => (isset($source_field['label']) ? $source_field['label'].' ('.$source_field['field_name'].')' : $source_field['field_name']) . " " . t("should be inserted into"),
        );

Instead of
taxonomy_vocabulary_2 should be inserted into
it now reads
Type of project (taxonomy_vocabulary_2) should be inserted into.