MFH: r499531
databases/mantis: Update to 2.21.0
Changes: https://mantisbt.org/bugs/changelog_page.php?project=mantisbt&version=2.20.1
Changes: https://mantisbt.org/bugs/changelog_page.php?project=mantisbt&version=2.21.0
Security: CVE-2019-10905
Approved by: ports-secteam (miwi)