Add missing post “Schleuder 3.4.1 released”

_posts/2019-09-16-schleuder-3-4-1-released.md

+---
+layout: post
+title:  "Schleuder 3.4.1 released"
+date: "2019-09-16"
+---
+
+This release fixes two problems with the handling of emails containing “protected headers”, and it drops third-party signatures on OpenPGP keys when importing to prevent signature flooding (if your version of GnuPG is recent enough). 
+
+For all details please see the [changelog](https://0xacab.org/schleuder/schleuder/blob/master/CHANGELOG.md#341-2019-09-16).