Help: Remove redundant selection update when opening page

Since the selection already gets updated in AbstractView::keydown_event
and AbstractView::mousedown_event we don't have to update it again in
the MainWidget::open_url function.

This fixes a bug that causes the selection to "spaz out" when
scrolling too fast between pages.

Userland/Applications/Help/MainWidget.cpp

@@ -292,7 +292,6 @@ void MainWidget::open_url(URL const& url)
             auto browse_view_index = m_manual_model->index_from_path(path);
             if (browse_view_index.has_value()) {
                 m_browse_view->expand_tree(browse_view_index.value().parent());
-                m_browse_view->selection().set(browse_view_index.value());
 
                 String page_and_section = m_manual_model->page_and_section(browse_view_index.value());
                 window()->set_title(String::formatted("{} - Help", page_and_section));