Upgrade to Symfony 4.4

- disable autowiring for Event (because the Entry entity was injected)
- rename `getClient()` for test to `getTestClient()` to avoid error while overriding (from `BrowserKitAssertionsTrait`)

tests/Wallabag/CoreBundle/WallabagCoreTestCase.php

@@ -32,7 +32,7 @@ abstract class WallabagCoreTestCase extends WebTestCase
         return $this->client = static::createClient();
     }
 
-    public function getClient()
+    public function getTestClient()
     {
         return $this->client;
     }