Fix anonymous assistants
Fix anonymous assistants

GtkAssistant supports not showing the sidebar with the page
titles (if the page have no titles). Unfortunately, we were
hiding the sidebar in this case, but still rendering the frame
behind it, leading to a broken appearance.

jigpu/gtk,davidgumberg/gtk,alexlarsson/gtk,ahodesuka/gtk,davidgumberg/gtk,davidgumberg/gtk,davidgumberg/gtk,jadahl/gtk,chergert/gtk,chergert/gtk,ahodesuka/gtk,ahodesuka/gtk,ahodesuka/gtk,chergert/gtk,Adamovskiy/gtk,ebassi/gtk,Sidnioulz/SandboxGtk,ebassi/gtk,Adamovskiy/gtk,chergert/gtk,alexlarsson/gtk,jigpu/gtk,jigpu/gtk,Adamovskiy/gtk,davidgumberg/gtk,ebassi/gtk,grubersjoe/adwaita,Lyude/gtk-,alexlarsson/gtk,jessevdk/gtk,ahodesuka/gtk,grubersjoe/adwaita,ebassi/gtk,ebassi/gtk,Sidnioulz/SandboxGtk,jessevdk/gtk,msteinert/gtk,Sidnioulz/SandboxGtk,Lyude/gtk-,jessevdk/gtk,chergert/gtk,Lyude/gtk-,jadahl/gtk,grubersjoe/adwaita,jadahl/gtk,jigpu/gtk,jessevdk/gtk,jigpu/gtk,Sidnioulz/SandboxGtk,chergert/gtk,Sidnioulz/SandboxGtk,Lyude/gtk-,alexlarsson/gtk,Adamovskiy/gtk,jigpu/gtk,msteinert/gtk,Sidnioulz/SandboxGtk,davidgumberg/gtk,jessevdk/gtk,grubersjoe/adwaita,ahodesuka/gtk,davidgumberg/gtk,msteinert/gtk,Lyude/gtk-,ahodesuka/gtk,Lyude/gtk-,chergert/gtk,msteinert/gtk,grubersjoe/adwaita,jadahl/gtk,alexlarsson/gtk,msteinert/gtk,Adamovskiy/gtk,jadahl/gtk,jigpu/gtk,chergert/gtk,alexlarsson/gtk,grubersjoe/adwaita,Adamovskiy/gtk,jadahl/gtk,ebassi/gtk,Adamovskiy/gtk,grubersjoe/adwaita,jessevdk/gtk,jadahl/gtk,Lyude/gtk-,jessevdk/gtk,msteinert/gtk,davidgumberg/gtk,ahodesuka/gtk,jadahl/gtk,alexlarsson/gtk,Lyude/gtk-,Adamovskiy/gtk,grubersjoe/adwaita,alexlarsson/gtk,jigpu/gtk