Fix a crasher as apparently "Qlist of QStringlist" is not registered with dbus:
QDBusPendingReply: type QList<QList<QString>> is not registered with QtDBus Aborted (core dumped)
QDBusPendingReply: type QList<QList<QString>> is not registered with QtDBus
Aborted (core dumped)
Follow-on: 866924f8, master only