fix syntax error, re !4

controllers/merge.php

@@ -21,7 +21,7 @@ final class MergeController extends TracToGitlab\GitlabController
             Sidebar::get()->addWidget(new TemplateWidget(
                 'Aus dem Cache',
                 $this->get_template_factory()->open(
-                    $this->get_default_template('sidebar'),
+                    $this->get_default_template('sidebar')
                 ),
                 ['time' => time()]
             ));