While that fixes the drkonqi bug just fine I am not sure that is the best fix for the problem. As I understand it KPasswordLineEdit doesn't set itself to StrongFocus, seeing as it is a replacement for QLineEdit that seems inconsistent and should be rectified though. IOW: I think KPasswordLineEdit should be changed to set a StrongFocus by default, same as QLineEdit.
QLineEdit has Qt::StrongFocus policy and it is the focus proxy of KPasswordLineEdit. My impression was that KPasswordLineEdit then automatically also had Qt::StrongFocus.
Appearantly, the policy is propagated in the other direction, so a correct fix would be to change the focus policy in kwidgetsaddons, see https://cgit.kde.org/kwidgetsaddons.git/tree/src/kpasswordlineedit.cpp#n88
Testing would need to confirm that this doesn't open password dialogs with the password line focussed by default.