Do not insert newline when item is empty
Do not insert newline when item is empty

This change is necessary when we remove unused imports (`use std::{};`).

graydon/rust,SingingTree/rustfmt,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,rust-lang/rustfmt,SingingTree/rustfmt,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,rust-lang/rustfmt