Comment 2 for bug 1594222

https://github.com/charybdis-ircd/charybdis-ircd.github.io/blob/master/_posts/2016-04-02-charybdis-3.5.1-release.md

My mistake. I pasted the wrong release. It's covered on the release notes as well but the details weren't as specific: http://charybdis.io/2016/04/02/charybdis-3.5.1-release.html

It is a known issue and I have the package you maintain running on a private server at the moment and it had been configured to only use SSL connections. When I asked on freenode the answer was direct about the fix which was made to correct the issue.