tree: Fix network startup

See [1].

The network service providers (network.service, mxvlan.service,
unbound.service) are pulled from multi-user.target (not from
network.target).

network.service pulls network.target so that other services might use
"After=network.target" (only for shutdown order).

network.service, which has DefaultDependencies=no, needs to order iteslf
behind sysinit.target, so that the network devices are available.

[1]: https://systemd.io/NETWORK_ONLINE/

misc_systemd_units/mxvlan.service

@@ -1,6 +1,6 @@
 [Unit]
-Wants=network.service
-After=network.service
+DefaultDependencies=no
+After=sysinit.target
 Before=network.target
 
 [Service]
@@ -11,5 +11,5 @@ ExecStop=/usr/sbin/mxvlanctl stop
 ExecReload=/usr/sbin/mxvlanctl restart
 
 [Install]
-WantedBy=network.target
+WantedBy=multi-user.target
 

misc_systemd_units/network.service

@@ -1,5 +1,8 @@
 [Unit]
 DefaultDependencies=no
+After=sysinit.target
+Before=network.target
+Wants=network.target
 
 [Service]
 EnvironmentFile=/etc/local/mxhost.conf
@@ -12,4 +15,4 @@ ExecStart=/sbin/ip route add default via 141.14.16.128
 ExecStop=/sbin/ip addr del ${MX_IPADDR}/20 dev ${MX_NETDEV}
 
 [Install]
-WantedBy=network.target
+WantedBy=multi-user.target

misc_systemd_units/unbound.service

@@ -1,5 +1,7 @@
 [Unit]
-After=network.service
+DefaultDependencies=no
+After=sysinit.target
+Before=network.target
 
 [Service]
 Type=forking
@@ -8,5 +10,5 @@ ExecStart=/usr/sbin/unbound
 PIDFile=/var/unbound/unbound.pid
 
 [Install]
-WantedBy=network.target
+WantedBy=multi-user.target