Fix "Cannot find a resource matching link[/etc/quantum/plugins/...]" (bnc#830870)

(This is a simpler fix for the same issue as #96, *and* I have tested that it works for my use case)

In some cases (if :quantum_server is false) we subscribed to
resources before they were defined.

Moved the subscription to a late point when the link and the main
config file are defined.

https://bugzilla.novell.com/show_bug.cgi?id=830870