##############################
# Sep 30 14:01:15 2021 GMT
##############################
Check yourself file "ca.crt" with
openssl x509 -enddate -noout -in ca.crt
Useful links:
* https://blog.devgenius.io/rhel-centos-7-fix-for-lets-encrypt...
* https://www.openssl.org/blog/blog/2021/09/13/LetsEncryptRoot...
* https://scotthelme.co.uk/lets-encrypt-old-root-expiration/
* the discussion in HN at https://hn.algolia.com/?dateRange=pastMonth&page=0&prefix=fa...
btw: on Centos 7 server you NEED to update package: ca-certificates