Remove old or unnecessary configuration settings

include/class.config.php

include/class.format.php

include/class.ticket.php

include/i18n/en_US/config.yaml

include/staff/settings-tickets.inc.php

include/staff/ticket-view.inc.php

include/upgrader/streams/core.sig

include/upgrader/streams/core/61c9d5d7-6de40a4d.patch.sql

setup/inc/class.installer.php

setup/inc/streams/core/install-mysql.sql