message: Fix CI error: Prevent "unused imports" in --no-default-features.
diff: @@ -4,6 +4,7 @@ use crate::config::Host;
  use crate::config::SslMode;
  use crate::connection::{Request, RequestMessages};
  use crate::copy_out::CopyOutStream;
  +#[cfg(feature = "runtime")]
  use crate::keepalive::KeepaliveConfig;
  use crate::query::RowStream;
  use crate::simple_query::SimpleQueryStream;
  