This happens in othe packages - well, not the FTBFS, but the error, like getmail. It's been reported in other distros as well, e.g. see https://bugs.archlinux.org/task/65976.
Maybe re-assign to libssl1.1?
- Bug#954533: python-tornado: FTBFS: dh_auto_test: error: pyb... Lucas Nussbaum
- Bug#954533: This is likely libssl1.1 problem Iustin Pop
