[Admin] Update your client software to continue using Let's Encrypt

Hi,

According to our records, the software client you're using to get Let's
Encrypt TLS/SSL certificates issued or renewed at least one HTTPS certificate
in the past two weeks using the ACMEv1 protocol. Here are the details of one
recent ACMEv1 request from each of your account(s):

Client IP address: 116.203.42.244

User agent: CertbotACMEClient/0.23.0 (certbot; Ubuntu 18.04.3 LTS) Authenticator/standalone Installer/None (renew; flags: n) Py/3.6.8

Hostname(s): "cloud.ffnw.de","dev.ffnw.de","firmware.ffnw.de","office.ffnw.de","repo.ffnw.de"

Request time: 2020-02-14 02:21:40 UTC

Beginning June 1, 2020, we will stop allowing new domains to validate using
the ACMEv1 protocol. You should upgrade to an ACMEv2 compatible client before
then, or certificate issuance will fail. For most people, simply upgrading to
the latest version of your existing client will suffice. You can view the
client list at: https://letsencrypt.org/docs/client-options/

If you're unsure how your certificate is managed, get in touch with the
person who installed the certificate for you. If you don't know who to
contact, please view the help section in our community forum at
https://community.letsencrypt.org/c/help and use the search bar to check if
there's an existing solution for your question. If there isn't, please create
a new topic and fill out the help template.

ACMEv1 API deprecation details can be found in our community forum:
https://community.letsencrypt.org/t/end-of-life-plan-for-acmev1

As a reminder: In the future, Let's Encrypt will be performing multiple
domain validation requests for each domain name when you issue a certificate.
While you're working on migrating to ACMEv2, please check that your system
configuration will not block validation requests made by new Let's Encrypt IP
addresses, or block multiple matching requests. Per our FAQ
(https://letsencrypt.org/docs/faq/), we don't publish a list of IP addresses
we use to validate, and this list may change at any time.

To receive more frequent updates, subscribe to our API Announcements:
https://community.letsencrypt.org/t/about-the-api-announcements-category

Thank you for joining us on our mission to create a more secure and privacy-
respecting Web!

All the best,

Let's Encrypt

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