Qt 5.15 carried a change that renamed a getter for the socket error. In
a later relase that change was reverted (to be less ambiguous) thus now
those that had picked up the change in API had to change their code.
This has now been reverted [0] and thus the consumers also have to
revert their changes…
[0] https://codereview.qt-project.org/c/qt/qtbase/+/289693