Comment # 1 on bug 1180724 from Martin Wilck

Note: on recent TW, the following change has been made in python3-sip:

* Sat Oct 10 2020 Benjamin Greiner <code@bnavigator.de>
- Only build the PyQt4 and PyQt5 modules for older distros

With this change, the attached patch isn't necessary any more, because 
/usr/lib64/python3.x/site-packages/PyQt4/sip.so, and thus "import PyQt4" fails
already (see patch description).