Remove errant import breaking the build.

Author: LegNeato

juniper/src/schema/model.rs

@@ -3,7 +3,6 @@ use std::{borrow::Cow, fmt};
 use fnv::FnvHashMap;
 #[cfg(feature = "graphql-parser-integration")]
 use graphql_parser::schema::Document;
-use graphql_parser::schema::ObjectType;
 
 use crate::{
     ast::Type,