We have too many branches and too few maintainers to be able to treat
old-stable branches as fully supported.
Helps: #5352
Signed-off-by: Simon McVittie <smcv@collabora.com>
The Matrix room is just as public as the old IRC channel, which makes it
just as unsuitable for reporting security vulnerabilities as IRC.
Signed-off-by: Simon McVittie <smcv@collabora.com>
If we can get people to report security issues privately, then we can do
coordinated disclosure instead of having to rush to fix issues that are
already known to the public.
