fix: avoid rendering error caused by incomplete data

templates/administrative/assignment/index.html.twig

@@ -94,11 +94,15 @@
                         <td>
                             {% if assignment.pickup %}
                                 {% set pickup = assignment.destination.pickup(assignment.pickup) %}
+                                {% if pickup %}
                                     <a href="{{ path('app_administrative_assignment_detail', { 'uuid': assignment.uuid, 'r': return_url() }) }}">
                                         <span class="whitespace-nowrap">ab {{ pickup.city }}</span>
                                         <br>
                                         {{ pickup.time }}
                                     </a>
+                                {% else %}
+                                    <span class="text-red-500">ungültiger Zustieg</span>
+                                {% endif %}
                             {% else %}
                                 -
                             {% endif %}