Bug#1025019: python-aiosmtpd: (autopkgtest) needs update for python3.11: Can't decode base64

[Charlemagne Lasse]

Control: tags -1 + fixed-upstream patch

Patch can be found at
https://github.com/aio-libs/aiosmtpd/commit/827f2321b7a926f3e8ba2aad6387b36c7c2e0b9a.patch