Fix "since" field for `Once::is_complete`'s `#[stable]` attribute
Fix "since" field for `Once::is_complete`'s `#[stable]` attribute

It was accidentally merged with the wrong version.

aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust