The retry logic returns an "acme: no more retries for ..." error in some cases, while *Error type in others. This change makes retries always return the last error as received from the CA server, if available. No change in returned values of successful requests. Change-Id: I3df2cb332a3e2739bba457c0ee50d7ca5bd836d9 Reviewed-on: https://go-review.googlesource.com/119975 Reviewed-by: Maciej Dębski <maciejd@google.com> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Run-TryBot: Alex Vaghin <ddos@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>