Desktop and Login Wallpapers

I was doing some tweaking of Ubuntu and I ran this command to disable the Guest session:

echo allow-guest=false | sudo tee -a /usr/share/lightdm/lightdm.conf.d/50-ubuntu.conf

Now that I've done this, the login screen only shows the default wallpaper, rather than matching whatever I set my desktop wallpaper to. I've tried googling for this issue and I can't seem to find anything for this specific context. How do I make it so that the login screen will go back to matching my desktop wallpaper?