Don't pass NULL to gdk_window_set_title
Don't pass NULL to gdk_window_set_title

That is not allowed. This is fallout from a recent change
that makes GtkWindow listen for title changes in its
headerbar.

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