Small improvements

app/Domains/Event/Controllers/CreateController.php

@@ -41,7 +41,8 @@ class CreateController extends CommonController {
         $payPerDay = $request->input('eventPayPerDay');
         $payDirect = $request->input('eventPayDirectly');
 
-        $billingDeadline = $eventEnd->modify('+6 weeks');
+        $billingDeadline = clone $eventEnd;
+        $billingDeadline->modify('+6 weeks');
 
         $createRequest = new CreateEventRequest(
             $request->input('eventName'),

app/Domains/Event/Controllers/SignupController.php

@@ -97,7 +97,8 @@ class SignupController extends CommonController {
         );
 
         $signupRequest = new SignUpRequest(
-            $event,$registrationData['userId'],
+            $event,
+            $registrationData['userId'] ?? null,
             $registrationData['vorname'],
             $registrationData['nachname'],
             $registrationData['pfadiname'],