ssh: fixing a small typo in connection.go
ssh: fixing a small typo in connection.go

Change-Id: Iffbed7e16a8bb32c5ff7c393f3b6ad7dcffc69ac
Reviewed-on: https://go-review.googlesource.com/44340
Reviewed-by: Han-Wen Nienhuys <3269a793d567baa2fa5b041e3e5e0a5039790a2f@google.com>
Run-TryBot: Han-Wen Nienhuys <3269a793d567baa2fa5b041e3e5e0a5039790a2f@google.com>

ScriptRock/crypto,golang/crypto,golang/crypto,ScriptRock/crypto,golang/crypto