Release 2.0.9 (#3922)

* fix api definition
* include customer number in validation message
* fix doctrine deprecation, prepare for DBAL 4
* added DataSubscriberInterface to identify certain doctrine subscribers

src/Doctrine/DataSubscriberInterface.php

@@ -0,0 +1,18 @@
+<?php
+
+/*
+ * This file is part of the Kimai time-tracking app.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace App\Doctrine;
+
+/**
+ * Used to identify EventSubscribers, that work upon EntityManager events and listen on data changes.
+ * These Subscribers will deactivated on batch imports, for performance gains and reduced DB queries.
+ */
+interface DataSubscriberInterface
+{
+}