Merge PR #328 from @zonky2

Fix PHP 8 warning

src/DcGeneral/Dca/Builder/DataDefinitionBuilder.php

@@ -3,7 +3,7 @@
 /**
  * This file is part of contao-community-alliance/dc-general.
  *
- * (c) 2013-2015 Contao Community Alliance.
+ * (c) 2013-2023 Contao Community Alliance.
  *
  * For the full copyright and license information, please view the LICENSE
  * file that was distributed with this source code.
@@ -15,7 +15,8 @@
  * @author     Tristan Lins <[email protected]>
  * @author     David Molineus <[email protected]>
  * @author     Stefan Heimes <[email protected]>
- * @copyright  2013-2015 Contao Community Alliance.
+ * @author     Ingolf Steinhardt <[email protected]>
+ * @copyright  2013-2023 Contao Community Alliance.
  * @license    https://github.com/contao-community-alliance/dc-general/blob/master/LICENSE LGPL-3.0
  * @filesource
  */
@@ -76,7 +77,7 @@ public function build(ContainerInterface $container, BuildDataDefinitionEvent $e
 
         // Check if we have to force the diff.
         if (
-            ($groupRightForceDiff == true || (\is_array($groupRightForceDiff) && $groupRightForceDiff[0] == true))
+            ($groupRightForceDiff == true || (\is_array($groupRightForceDiff) && !empty($groupRightForceDiff[0])))
             && $palettesDefinition
             && $palettesDefinition->hasLegend('table')
             && $palettesDefinition->getLegend('table')->hasProperty('database_pages_check')