fix handling of baloo starting after elisa
Summary:
if Baloo is configured inactive at elisa start and later is enabled,
fix baloo management such that we correctly query Baloo for a list of
audio files
BUG: 387437
Test Plan: manual test allow to get the music files from baloo
Reviewers: astippich, januz, aspotashev
Reviewed By: astippich
Tags: Elisa
Differential Revision: https://phabricator.kde.org/D15298