message: Remove reacted with text when shortcode missing
  If we don't have the shortcode for some emoji, don't show any "reacted with X"
  text in the reaction tooltip.
  Fixes
diff: @@ -46,7 +46,7 @@ export default class ReactionsRowButtonTooltip extends React.PureComponent {
  const { name } = room.getMember(reactionEvent.getSender());
  senders.push(name);
  }
  - const shortName = unicodeToShortcode(content) || content;
  + const shortName = unicodeToShortcode(content);
  tooltipLabel = <div>{_t(
  "<reactors/><reactedWith>reacted with %(shortName)s</reactedWith>",
  {
  @@ -59,6 +59,9 @@ export default class ReactionsRowButtonTooltip extends React.PureComponent {
  </div>;
  },
  reactedWith: (sub) => {
  + if (!shortName) {
  + return null;
  + }
  return <div className="mx_ReactionsRowButtonTooltip_reactedWith">
  {sub}
  </div>;
  