ui: system: When canceling search stay on current page

Tests:

- On app and system pages, canceling the search using the close button at the
end of the search bar will remove the search tags but will stay on the same
page.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>

plinth/templates/tags.html

@@ -34,7 +34,7 @@
             {% endfor %}
           </ul>
         </div>
-        <a href="{% url 'apps' %}" aria-label="{% trans 'Clear all tags' %}"
+        <a href="{{ active_section_url }}" aria-label="{% trans 'Clear all tags' %}"
            class="btn-close" type="button"></a>
       </div>
     </div>