refactor import queue to use explicit block import references

substrate/core/network/src/service.rs

@@ -130,7 +130,6 @@ impl<B: BlockT + 'static, S: Specialization<B>, H: ExHashT> Service<B, S, H> {
 		protocol_id: ProtocolId,
 		import_queue: I,
 	) -> Result<Arc<Service<B, S, H>>, Error> {
-		let chain = params.chain.clone();
 		let import_queue = Arc::new(import_queue);
 		let handler = Arc::new(Protocol::new(
 			params.config,
@@ -153,7 +152,6 @@ impl<B: BlockT + 'static, S: Specialization<B>, H: ExHashT> Service<B, S, H> {
 
 		// connect the import-queue to the network service.
 		let link = ::import_queue::NetworkLink {
-			client: chain,
 			sync: Arc::downgrade(service.handler.sync()),
 			context: Arc::downgrade(&service),
 		};