testiso: remove `[Unit]` from NM keyfile
Harmless but confusing copy/paste remnant.
Fixes: ("testiso: add --add-nm-keyfile for NM keyfile propagation testing")
@@ -183,8 +183,7 @@ RequiredBy=multi-user.target`)
var nmConnectionId = "CoreOS DHCP"
var nmConnectionFile = "coreos-dhcp.nmconnection"
-var nmConnection = fmt.Sprintf(`[Unit]
-[connection]
+var nmConnection = fmt.Sprintf(`[connection]
id=%s
type=ethernet
