package/confd: allow avahi (mDNS/SD) and sshd to be enabled by default

The idea is to, as a plain Infix default, start up devices with DHCP and
IPv4LL/ZeroConf and IPv6 link-local address.  Using mDNS the user can
then and push a NETCONF configuration over SSH.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

package/confd/clean-etc

@@ -7,7 +7,7 @@
 # ... except for some core services
 reserved()
 {
-    for svc in dnsmasq getty klish lldpd nginx sysklogd sysrepo; do
+    for svc in avahi dnsmasq getty klish lldpd nginx ssdpd sshd sysklogd sysrepo; do
 	[ "$1" = "${svc}.conf" ] && return 0
     done