Bug#940524: schleuder: fails to recognize keywords in mails with protected headers and empty subject

[Georg Faerber]

Package: schleuder
Version: 3.4.0-1
Forwarded: https://0xacab.org/schleuder/schleuder/issues/431
Tags: fixed-upstream buster

Schleuder fails to recognize keywords in mails with protected headers
and empty subject. A fix was released upstream.