Comment # 1 on bug 1049975 from Wolfgang Bauer

(In reply to Dirk Weber from comment #0)
> It seems like an error in storing the cookie settings.

Indeed.
Should be easy to fix then.

> I do not know if this is relevant, but the ~/.config/Trolltech.conf contains 
> usr\lib64\kde4\kded_kcookiejar.so which looks like
> /usr/lib64/kde4/kded_kcookiejar.so

No, this is irrelevant.
Konqueror is KDE Frameworks5/Qt5 based in 17.04.2, ~/.config/Trolltech.conf
contains the Qt4 settings and is not used at all by Qt5.