make success flash message optional, resolves #403

UPGRADE.md

@@ -5,11 +5,13 @@
 
 ### Global Changes
 - [DEPRECATION REMOVED] removed `FormDefinition::setMailLayout`. Please migrate to output workflows before updating
-- [IMPROVEMENTS] Recommended folder structure by symfony adopted
+- [IMPROVEMENT] Recommended folder structure by symfony adopted
+- [IMPROVEMENT] Make success flash message optional [#403](https://github.com/dachcom-digital/pimcore-formbuilder/issues/403)
 - [FUNNEL] Route include changed from `@FormBuilderBundle/Resources/config/pimcore/routing_funnels.yml` to `@FormBuilderBundle/config/pimcore/routing_funnels.yaml`
 - [BC BREAK] Mail Layout Editor: While there is a migration, we're not able to migrate container (fieldset, repeater) fields. Please adjust your output workflow channels manually.
 - [BC BREAK] All views are lowercase/underscore now (`email/form_data.html.twig`, `form/elements/dynamic_multi_file/*`)
 
+
 ### New Features
 - Mail Layout Editor, see [#390](https://github.com/dachcom-digital/pimcore-formbuilder/issues/398)
   - If [Emailizr](https://github.com/dachcom-digital/pimcore-emailizr) is installed, formbuilder will use it automatically to transform html tables

public/js/extjs/components/successMessageToggleComponent.js

@@ -211,7 +211,7 @@ Formbuilder.extjs.components.successMessageToggleComponent = Class.create({
             anchor: '100%',
             labelAlign: 'top',
             summaryDisplay: true,
-            allowBlank: false,
+            allowBlank: true,
             emptyText: t('form_builder_success_message_text_empty'),
             value: this.data ? this.data.flashMessage : null,
             flex: 1,