Ignore baloo urls created from new KIO model

Summary:
For now ignore baloo urls that was created by new KIO::KFilePlacesModel,
until we make use of new KIO API.

BUG: 387888

Test Plan:
Open any KIO file dialog using the new API.
Runs dolphin v17.12.0
Make sure that baloo urls does not appear duplicated

Reviewers: ngraham, elvisangelaccio

Reviewed By: ngraham, elvisangelaccio

Subscribers: cfeck, elvisangelaccio, ervin, mlaurent, #dolphin

Differential Revision: https://phabricator.kde.org/D9347