fixed bug when no domains exist

composer.json

@@ -2,7 +2,7 @@
   "name": "24unix/bindapi",
   "description": "manage Bind9 DNS server via REST API",
   "version": "2023.0.1",
-  "build_number": "334",
+  "build_number": "335",
   "authors": [
     {
       "name": "Micha Espey",

src/Repository/DomainRepository.php

@@ -245,7 +245,8 @@ readonly class DomainRepository
 			$statement = $this->databaseConnection->getConnection()->prepare(query: $sql);
 			$statement->execute();
 			$result = $statement->fetch();
-			return $result['length'];
+            // if there are not yet any domains, just return 30
+			return $result['length'] ?? 30;
 		} catch (PDOException $e) {
 			exit($e->getMessage());
 		}