Correct an empty array check

Author: Stefan Heimes

src/Controller/DatabasePopupController.php

@@ -191,8 +191,9 @@ public function showNormalDatabase()
         }
 
         // If no table is found skip the view
-        if (count($this->arrSyncSettings['syncCto_CompareTables']['recommended']) == 0
-            && count($this->arrSyncSettings['syncCto_CompareTables']['nonRecommended']) == 0
+        if (
+            count($this->arrSyncSettings['syncCto_CompareTables']['recommended'] ?? []) == 0
+            && count($this->arrSyncSettings['syncCto_CompareTables']['nonRecommended'] ?? []) == 0
         ) {
             unset($this->arrSyncSettings['syncCto_CompareTables']);
             $this->arrSyncSettings['syncCto_SyncDeleteTables'] = array();