partial fix for accentuated characters in file name on Windows

Summary: partial fix to try to get accentuated file names to work with TagLibWriter

Test Plan: no tests

Reviewers: bruns, astippich

Reviewed By: astippich

Subscribers: kde-frameworks-devel, Baloo

Tags: Frameworks, Baloo

Differential Revision: https://phabricator.kde.org/D26054