rpc: add back rpc logger (#4952)

Co-authored-by: Bastian Köcher <git@kchr.de>

substrate/client/rpc-servers/src/lib.rs

@@ -224,8 +224,9 @@ where
 					),
 				};
 
-				let rpc_middleware =
-					RpcServiceBuilder::new().option_layer(middleware_layer.clone());
+				let rpc_middleware = RpcServiceBuilder::new()
+					.rpc_logger(1024)
+					.option_layer(middleware_layer.clone());
 				let mut svc =
 					service_builder.set_rpc_middleware(rpc_middleware).build(methods, stop_handle);