Add CLOSED setting

templates/base.html

@@ -33,7 +33,7 @@
           </select>
 
           <a href="/logout" class="btn">Uitloggen</a>
-          <button class="btn-primary" type="submit" id="save-button">Opslaan</button>
+          {% if CLOSED %}<br>Uitzendingen kunnen niet meer worden ingezonden{% else %}<button class="btn-primary btn-disabled" type="submit" id="save-button" disabled>Opslaan</button>{% endif %}
           <div class="alert alert-info" id="js-message" style="display: none;"></div>
         </div>