fix some warning in phpUnit, an other try ...

setup/inc/class.setup.inc.php

@@ -253,6 +253,7 @@ private static function session_start()
 			case PHP_SESSION_DISABLED:
 				throw new \ErrorException('EGroupware requires PHP session extension!');
 			case PHP_SESSION_NONE:
+				if (headers_sent()) return true;
 				ini_set('session.use_cookie', true);
 				session_name(self::SESSIONID);
 				session_set_cookie_params(0, '/', self::cookiedomain(),