message: Message editing: preserve strikethrough as well
diff: @@ -110,6 +110,9 @@ function parseHtmlMessage(html, room) {
  case "CODE":
  parts.push(new PlainPart(`\`${n.textContent}\``));
  break;
  + case "DEL":
  + parts.push(new PlainPart(`<del>${n.textContent}</del>`));
  + break;
  default:
  parts.push(new PlainPart(n.textContent));
  break;
  