Selected song after removing an album from the playlist

Hi there,

I found a small problem in your otherwise very nice application.

**Steps to replicate:**
1. Open application.
2. Add both albums to the playlist.
3. Start playing.
4. Remove the played album from the playlist.
5. Start playing again.

What is played now is still the song that has been playing when the album was removed from the playlist instead of the currently selected song.

I added the tiny fix needed to make this working and the corresponding test case.

With kind regards,
Marc