change test to slider for disk create

app/UI/Disk/Forms/UpdateForm.php

@@ -43,7 +43,6 @@ class UpdateForm extends BaseForm implements ClientArea
         $this->setFormType('update');
         $this->setProvider(new DiskProvider());
         $this->initFields();
-        $this->loadDataToForm();
 
         logModuleCall(
             'proxmoxCloud',
@@ -53,6 +52,7 @@ class UpdateForm extends BaseForm implements ClientArea
             parent::getFormData()['size']
         );
 
+        $this->loadDataToForm();
     }
 
     public function getAllowedActions()