net-im/py-matrix-synapse: Update to 1.24.0, Fix security issue

Changelog: https://github.com/matrix-org/synapse/blob/v1.24.0/CHANGES.md

PR: 251768
Submitted by: contact@evilham.com
Approved by: Sascha Biberhofer <ports@skyforge.at> (maintainer)
MFH: 2020Q4
Security: cfa0be42-3cd7-11eb-9de7-641c67a117d8