[BUGFIX] Fix possible exception with additional validators or spam prevention methods

If someone extends powermail with own validators and is using "show confirmation page" it could happen that the error
'Exception while property mapping at property path "": It is not allowed to map property "answers". You need to use $propertyMappingConfiguration->allowProperties('answers') to enable mapping of this property.'
pops up. Problem is basicly because createAction with its validators forwarded the request to confirmationAction with the same validators

Author: einpraegsam

Classes/Controller/FormController.php

@@ -455,6 +455,22 @@ protected function forwardIfFormParamsDoNotMatchForOptinConfirm(Mail $mail = nul
         }
     }
 
+    /**
+     * Always forward to formAction if a validation fails. Otherwise it could happen that when
+     * a validator for createAction fails, confirmationAction is called (if function is turned on) and same validators
+     * are firing again
+     *
+     * @return void
+     * @throws StopActionException
+     */
+    protected function forwardToReferringRequest()
+    {
+        $originalRequest = clone $this->request;
+        $this->request->setOriginalRequest($originalRequest);
+        $this->request->setOriginalRequestMappingResults($this->arguments->validate());
+        $this->forward('form');
+    }
+
     /**
      * Decide if the mail object should be persisted or not
      *        persist if