Another proposed fix for null/missing resource issue

I noticed that often in ChatView, we are using a Contact instance that has an Address with no resource. This is because that Contact is loaded from the roster, and no resource is set at that point. Contact does get updated with the latest presence data as it arrives, and setPresence() is called with the latest/highest priority resource string.

This change ensures that getAddress() calls on a Contact instance use the base address combined with the latest resource.