We forgot to include the qemu-block mailing list while adding
this section in commit 076a0fc3. Fix this.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200630133912.9428-2-f4bug@amsat.org>