remove spurious extern crate statement

Author: eeeeeta

src/lib.rs

@@ -4,8 +4,6 @@ extern crate serde_derive;
 extern crate spade;
 #[cfg(feature = "postgis-integration")]
 extern crate postgis;
-#[cfg(feature = "geojson-integration")]
-extern crate geojson;
 
 pub use traits::ToGeo;
 pub use types::*;