mail/sympa: Update to 6.2.62

Changes: https://sympa-community.github.io/security/2021-001.html

PR: 255455
Submitted by: Geoffroy Desvernay <dgeo@centrale-marseille.fr> (maintainer)
MFH: 2021Q2 (security blanket)
Security: 31a7ffb1-a80a-11eb-b159-f8b156c2bfe9

(cherry picked from commit 681b324cbdc50eedea91e77948e543ac36baab41)