Fix #2946: Use Yii2 default timezone handling

protected/humhub/components/Application.php

@@ -89,16 +89,4 @@ class Application extends \yii\web\Application
 
         return parent::beforeAction($action);
     }
-
-    /**
-     * @inheritdoc
-     */
-    public function preInit(&$config)
-    {
-        if (!isset($config['timeZone']) && date_default_timezone_get()) {
-            $config['timeZone'] = date_default_timezone_get();
-        }
-
-        parent::preInit($config);
-    }
 }

protected/humhub/docs/CHANGELOG_DEV.md

@@ -12,6 +12,7 @@ HumHub Change Log (DEVELOP)
 - Chng: Removed `jquery-placeholder` asset and dependency
 - Chng: Removed `atwho` asset and dependency
 - Cnng: Removed old IE support
+- Fix #2946: Use Yii2 default timezone handling