dns: tls - Raise log level to error, and log to journald

By default the loglevel is 5 (notice).

emerg (0)
alert (1)
crit (2)
err (3)
warning (4)
notice (5)
info (6)
debug (7)

files/dns/tls_proxy/dns.conf

@@ -2,7 +2,7 @@ setuid=stunnel4
 setgid=stunnel4
 pid=/var/run/stunnel4/dns.pid
 cert=/etc/stunnel/dns.pem
-output=/var/log/stunnel4/dns.log
+debug=3
 socket = l:TCP_NODELAY=1
 socket = r:TCP_NODELAY=1