fix: enforce profile completion of applicant in all situations

templates/booking/create/error.html.twig

@@ -13,7 +13,7 @@
         } %}
 
         {# hx-boost disabled for cross-origin #}
-        <a href="{{ returnUrl }}" hx-boost="false" class="button button--secondary">
+        <a href="{{ returnUrl }}" hx-boost="false" class="button button--primary">
             Zurück
         </a>
     </div>