message: Fix wrong handling of missing/empty titleLink option value
diff: @@ -27,7 +27,7 @@ export const toolbar = (context: DefaultThemeRenderContext, props: PageEvent<Ref
  <li class="state failure">The search index is not available</li>
  </ul>
  - <a href={context.options.getValue("titleLink") ?? context.relativeURL("index.html")} class="title">
  + <a href={context.options.getValue("titleLink") || context.relativeURL("index.html")} class="title">
  {props.project.name}
  </a>
  </div>
  