message: XLIFF: Fix bogus error if translation omits markup
  Don't show bogus markup error if translation of a translation with XLIFF
  markup doesn't contain any (possibly yet).
diff: @@ -80,7 +80,16 @@ bool set_node_text(xml_node node, const std::string& text, bool isPlainText)
  {
  remove_all_children(node);
  auto result = node.append_buffer(text.c_str(), text.size(), parse_default, encoding_utf8);
  - return result.status == status_ok;
  + switch (result.status)
  + {
  + case status_no_document_element:
  + node.text() = s.c_str();
  + return true;
  + case status_ok:
  + return true;
  + default:
  + return false;
  + }
  }
  }
  