certbot更新错误

自动更新总是提示这个错误。

root@vultr:~/certbot# ./certbot-auto
Upgrading certbot-auto 0.29.1 to 0.34.2...
Couldn't verify signature of downloaded certbot-auto. Command '[u'openssl', u'dgst', u'-sha256', u'-verify', u'/tmp/tmp.7MOfNZ80uw/public_key.pem', u'-signature', u'/tmp/tmp.7MOfNZ80uw/letsencrypt-auto.sig', u'/tmp/tmp.7MOfNZ80uw/letsencrypt-auto']' returned non-zero exit status 1

　　

使用下面语句解决

./certbot-auto  --no-self-upgrade