Don't load the moodbar if the song was stopped
When an async moodbar load completes, it checks to see if the song is still playing and should update the UI.
It however failed to check if the song was stopped, so it would load a moodbar when no song is playing.
It now checks the player state before emitting a change.
Merge pull request #4669 from TheUbuntuGuy/master

Don't load the moodbar if the song was stopped