[Fix bug] Validate field

Author: DHT-Uri

Block/Adminhtml/Slider/Edit/Tab/Design.php

@@ -111,7 +111,7 @@ protected function _prepareForm()
             'name'  => 'limit_number',
             'label' => __('Limit the number of products'),
             'title' => __('Limit the number of products'),
-            'class'    => 'validate-number validate-greater-than-zero'
+            'class'    => 'validate-number validate-zero-or-greater'
         ]);
 
         $fieldset->addField('display_additional', 'multiselect', [