Add default value for config.sitename in App::initHead
Add default value for config.sitename in App::initHead

- Protect $this->page['title'] even more

Co-Authored-By: MrPetovan <45351199efa1303728b40073c11ac70bf0527083@mrpetovan.com>
friendica/friendica,annando/friendica,tobiasd/friendica,fabrixxm/friendica,friendica/friendica,friendica/friendica,fabrixxm/friendica,annando/friendica,annando/friendica,friendica/friendica,fabrixxm/friendica,fabrixxm/friendica,tobiasd/friendica,tobiasd/friendica,tobiasd/friendica,annando/friendica,annando/friendica,tobiasd/friendica,fabrixxm/friendica,friendica/friendica