ssh: Treat "connection refused" on Windows
Slightly relax the conditions under which an error is considered to indicate that the SSH agent is not running, to accommodate differences in the API of named pipes on Windows vs. Unix domain sockets.
Slightly relax the conditions under which an error is considered to indicate that the SSH agent is not running, to accommodate differences in the API of named pipes on Windows vs. Unix domain sockets.
REVIEW: clippy warns about return and simplify or_else to or
Rebase