Bug#1017907: ffado-mixer-qt4 fails to start with python 3.10

[Alexandre Lymberopoulos <lymber@gmail.com>]

Package: ffado-mixer-qt4
Version: 2.4.6-1
Followup-For: Bug #1017907

Dear Maintainer,

I confirm the mentioned bug. Benoît proposed a solution that seems legit.

Best, Alexandre

-- System Information:
Debian Release: bookworm/sid
  APT prefers testing
  APT policy: (900, 'testing'), (800, 'unstable'), (500, 'stable-security')
Architecture: amd64 (x86_64)

Kernel: Linux 6.0.0-3-amd64 (SMP w/4 CPU threads; PREEMPT)
Kernel taint flags: TAINT_WARN
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages ffado-mixer-qt4 depends on:
ii  ffado-dbus-server            2.4.6-1
ii  ffado-tools                  2.4.6-1
ii  python3                      3.10.6-1
ii  python3-dbus                 1.3.2-1
ii  python3-dbus.mainloop.pyqt5  5.15.7+dfsg-2
ii  python3-pyqt5                5.15.7+dfsg-2

ffado-mixer-qt4 recommends no packages.

ffado-mixer-qt4 suggests no packages.

-- no debconf information