fix wasm build

Author: sfackler

tokio-postgres/src/client.rs

@@ -25,7 +25,9 @@ use postgres_protocol::message::{backend::Message, frontend};
 use postgres_types::BorrowToSql;
 use std::collections::HashMap;
 use std::fmt;
+#[cfg(feature = "runtime")]
 use std::net::IpAddr;
+#[cfg(feature = "runtime")]
 use std::path::PathBuf;
 use std::sync::Arc;
 use std::task::{Context, Poll};