[TaglibExtractor] Feed non-ogg *.spx file into extractor test

Summary:
Binary files with .spx extension are detected as audio/speex as the type
has no file magic. Taglib will crash when trying to extract properties
from these files. ArcGIS datasets contain affected binary files.

Test Plan: ctest

Reviewers: Baloo, Frameworks, ngraham, astippich

Reviewed By: Baloo, ngraham, astippich

Subscribers: kde-frameworks-devel

Tags: Frameworks, Baloo

Differential Revision: https://phabricator.kde.org/D20914