message: known_hosts: Switch the documentation to stable.
  When making the stable release, the nightly docs won't be updated, yet.
  This makes sure that the link will work for the stable release.
diff: @@ -158,7 +158,7 @@ pub fn certificate_check(
  The {key_type_short_name} key fingerprint is: SHA256:{remote_fingerprint}\n\
  This fingerprint should be validated with the server administrator that it is correct.\n\
  {other_hosts_message}\n\
  - See https://doc.rust-lang.org/nightly/cargo/appendix/git-authentication.html#ssh-known-hosts \
  + See https://doc.rust-lang.org/stable/cargo/appendix/git-authentication.html#ssh-known-hosts \
  for more information.\n\
  ")
  }
  @@ -216,7 +216,7 @@ pub fn certificate_check(
  \n\
  {hostname} {key_type_name} {remote_host_key}\n\
  \n\
  - See https://doc.rust-lang.org/nightly/cargo/appendix/git-authentication.html#ssh-known-hosts \
  + See https://doc.rust-lang.org/stable/cargo/appendix/git-authentication.html#ssh-known-hosts \
  for more information.\n\
  ")
  }
  