Removing from playlist doesn't update UI correctly

[vrih]

When removing tracks from the playlist, the correct tracks are removed but the UI is not updated correctly. Half the selected tracks remain in the UI.

I suspect there's an issue of deleting items from a list while iterating through that list, throwing the index off.

To reproduce, have a playlist of about 10 tracks. Select the middle 5 and remove from playlist.

[vrih]

Pretty sure this is the issue. Will see if I can do this a better way.

https://github.com/daneren2005/Subsonic/blob/edge/app/src/main/java/github/daneren2005/dsub/fragments/SelectDirectoryFragment.java#L921