configure: post-release version bump
configure: post-release version bump

We forgot to do this after the 2.9.0 release...
(We recently[1] changed this policy.)

[1] https://git.gnome.org/browse/banshee/commit/?id=6f870f3f682bf8a107fbbc50bd42f83401004120

ixfalia/banshee,ixfalia/banshee,GNOME/banshee,ixfalia/banshee,Carbenium/banshee,arfbtwn/banshee,GNOME/banshee,Carbenium/banshee,babycaseny/banshee,stsundermann/banshee,babycaseny/banshee,stsundermann/banshee,babycaseny/banshee,arfbtwn/banshee,GNOME/banshee,babycaseny/banshee,arfbtwn/banshee,Carbenium/banshee,GNOME/banshee,dufoli/banshee,ixfalia/banshee,arfbtwn/banshee,GNOME/banshee,stsundermann/banshee,GNOME/banshee,dufoli/banshee,arfbtwn/banshee,arfbtwn/banshee,dufoli/banshee,dufoli/banshee,arfbtwn/banshee,dufoli/banshee,babycaseny/banshee,ixfalia/banshee,ixfalia/banshee,stsundermann/banshee,GNOME/banshee,ixfalia/banshee,babycaseny/banshee,dufoli/banshee,babycaseny/banshee,Carbenium/banshee,dufoli/banshee,stsundermann/banshee,GNOME/banshee,ixfalia/banshee,arfbtwn/banshee,stsundermann/banshee,stsundermann/banshee,stsundermann/banshee,dufoli/banshee,babycaseny/banshee,Carbenium/banshee,Carbenium/banshee