mail/mailman: security/bugfix update to 2.1.35

Changelog:
https://bazaar.launchpad.net/~mailman-coders/mailman/2.1/view/1873/NEWS#L8

Security: CVE-2021-42096
Security: CVE-2021-42097
Security: 8d65aa3b-31ce-11ec-8c32-a14e8e520dc7
MFH: 2021Q4
(cherry picked from commit 2f936c7f3fbb967061e410dfb216b796edb5d94a)