message: fix types around sending stickers
diff: @@ -1196,7 +1196,7 @@ export default class RoomView extends React.Component<IProps, IState> {
  });
  };
  - private injectSticker(url, info, text) {
  + private injectSticker(url: string, info: object, text: string) {
  if (this.context.isGuest()) {
  dis.dispatch({action: 'require_registration'});
  return;
  