message: Fix urls for the edition guide.
diff: @@ -150,7 +150,7 @@ your `Cargo.toml` and then rerun this command. Once all warnings have been fixed
  then you can re-enable the `edition` key in `Cargo.toml`. For some more
  information about transitioning to the {0} edition see:
  - https://rust-lang-nursery.github.io/edition-guide/editions/transitioning-your-code-to-a-new-edition.html
  + https://rust-lang-nursery.github.io/edition-guide/editions/transitioning-an-existing-project-to-a-new-edition.html
  ",
  edition,
  file,
  @@ -172,7 +172,7 @@ consider migrating to the {0} edition by adding `edition = '{0}'` to
  `Cargo.toml` and then rerunning this command; a more detailed transition
  guide can be found at
  - https://rust-lang-nursery.github.io/edition-guide/editions/transitioning-your-code-to-a-new-edition.html
  + https://rust-lang-nursery.github.io/edition-guide/editions/transitioning-an-existing-project-to-a-new-edition.html
  ",
  idioms,
  file,
  