[arch-general] Removal of ssmtp

[David Runge]

Hey all,

I have just removed ssmtp from [community].
Apart from it being unmaintained upstream, it has known security issues
(e.g. [1]).
I highly recommend _not_ using and removing it, in the case you have
been using it.

As replacements have a look at `pacman -Ss smtp-forwarder`.

Best,
David

[1] https://bugs.archlinux.org/task/60502