Remove forgotten traceback formatting, fixes #158

There used to be a try except in get_current_track_info, where-in the caught exception would be logged. The try-except is no longer there, and therefore the logging of the traceback needed to be remove. This was also the only use of the traceback module, so that import has been removed.

I consider this a bug-fix and will merge shortly. Juts putting it up here for reference.