Remove dead code

Summary: The code appears to do nothing.

Test Plan: builds, bookmarkmenu still works

Reviewers: Dolphin, meven, elvisangelaccio

Reviewed By: Dolphin, meven, elvisangelaccio

Subscribers: meven, kfm-devel

Tags: Dolphin

Differential Revision: https://phabricator.kde.org/D25347