econet: do not alloc macaddr via macoffset

iopsys-econet/base-files/etc/macoffset

 {
         "size" : 16,
         "autofill": true,
-        "wireless": true,
+        "wireless": false,
         "config": [
                 "network.lan",
-                "network.wan network.wan6",
-                "wireless.@wifi-iface[0]",
-                "wireless.@wifi-iface[1]"
+                "network.wan network.wan6"
         ]
 }