Don't draw tab gap
Don't draw tab gap

Tell GTK+ that we don't require a gap at the bottom of the active
tab.

https://bugzilla.gnome.org/show_bug.cgi?id=707922

DoctorJellyface/gnome-themes-standard,Distrotech/gnome-themes-standard,DoctorJellyface/gnome-themes-standard,Distrotech/gnome-themes-standard