Two issues with the letsencrypt plugin.
1. It is not possible to report any issue on github for this plugin. Please enable the issue feature for this repo.
2. The Debian package 'certbot' is not available in the omv-extras package repositiories. I have enabled the stable and testing repo, but both do not contain it. The omv-extras package repository MUST contain these packages and all dependencies like python-certbot, ...
1 - Thanks. Not sure why they were disabled
2 - I don't use this plugin but certbot is in the jessie-backports repo. I guess most letsencrypt users use the backports kernel? I would file an issue. There are almost 30 packages that install with certbot and I won't be the one maintaining those in the omv-extras repo. Someone else can if they want