Declare missing property

Author: fredden

app/code/Magento/Catalog/Test/Unit/Model/Category/DataProviderTest.php

@@ -72,6 +72,11 @@ class DataProviderTest extends TestCase
      */
     private $categoryFactory;
 
+    /**
+     * @var DataInterfaceFactory|MockObject
+     */
+    private $uiConfigFactory;
+
     /**
      * @var Collection|MockObject
      */