Fix runtime issue introduced in 2f812cb (gerrit:#19341)

Fix runtime issue introduced in 2f812cb (gerrit:#19341)

example/* sources have been removed but they are still imported
from app/Settings.qml. This creates the following error in the QML engine at runtime:
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Jan 04 14:20:57 h3ulcb afbd-settings@0.1[5140]: QQmlApplicationEngine failed to load component
Jan 04 14:20:57 h3ulcb afbd-settings@0.1[5140]: qrc:/Settings.qml:24 "example": no such directory
Jan 04 14:20:57 h3ulcb afbd-settings@0.1[5140]: QObject::connect: Cannot connect (null)::frameSwapped() to QLibWindowmanager::slotActivateWindow()
---

This patch fixes the runtime issue.

Change-Id: I793d5a8bb73b4257feba8b66b1ba2eb7db6db398
Signed-off-by: Stephane Desneux <stephane.desneux@iot.bzh>