fix: avoid redirect after failing booking data validation via API

src/Controller/Booking/EditController.php

@@ -97,9 +97,9 @@ class EditController extends AbstractController
                 }
 
                 $this->addFlash('success', 'Buchung erfolgreich aktualisiert');
-            }
 
-            return $this->redirectToRoute('app_booking_edit', ['id' => $id]);
+                return $this->redirectToRoute('app_booking_edit', ['id' => $id]);
+            }
         }
 
         return $this->render('booking/edit.html.twig', [