1. Open OpenSHH or WinSCP or whatever client you use.
2. Navigate to "System/Library/SpringBoardPlugins"
3. Rename "NowPlayingArtLockScreen.bundle" to "NowPlayingArtLockScreen_.bundle" or anything of that nature (best to not affect the name but just add a symbol of some kind)
4. Respring and it should work. No album covers anymore.