Remove background color for .frame
Remove background color for .frame

This was wrong, but until now harmless because GtkFrame was not painting
the background at all

rgcjonas/adwaita-semidark,ChrisCummins/gnome-themes-standard,ChrisCummins/gnome-themes-standard,rgcjonas/adwaita-semidark,DoctorJellyface/gnome-themes-standard,rgcjonas/adwaita-semidark,ChrisCummins/gnome-themes-standard,rgcjonas/adwaita-semidark,ChrisCummins/gnome-themes-standard,Distrotech/gnome-themes-standard,DoctorJellyface/gnome-themes-standard,ChrisCummins/gnome-themes-standard,Distrotech/gnome-themes-standard