fix exemple build
fix exemple build

rust-gnome/gtk,rust-gnome/glib,rtsuk/cairo,Susurrus/gtk,drewet/gtk,gkoz/rust-gnome-cairo,gkoz/gtk-rs-cairo,gkoz/gtk-rs-glib,EPashkin/rust-gnome-gtk,mitaa/gtk,insanebits/gtk,EPashkin/rust-gnome-gtk,EPashkin/rust-gnome-glib,gkoz/rust-gnome-gtk,drewet/gtk,insanebits/gtk,daa84/gtk,nicokoch/glib,LordSentox/gtk,Susurrus/glib,daa84/gtk,Susurrus/gtk,mitaa/gtk,gkoz/gtk-rs-gtk,rust-gnome/gtk,LordSentox/gtk,gkoz/gtk-rs-pango,gkoz/rust-gnome-gtk,gkoz/gtk-rs-gtk,gkoz/rust-gnome-glib,rust-gnome/cairo