acme/autocert: remove failed state entries

This change makes the Manager try creating a certificate
again, after a previously unsuccessful attempt.

The implementation is based on a timer, to prevent hitting
an ACME CA with too high QPS when under a heavy load.
The timer is hardcoded to 1 minute.

Fixes golang/go#17740.
Change-Id: I46a49201cf423be3360633a89209d7b2bccc1d76
Run-TryBot: Alex Vaghin <>
TryBot-Result: Gobot Gobot <>
Reviewed-by: Brad Fitzpatrick <>
2 files changed