[BUG] Subscription Reconciler bugs found while migrating.

[n3wscott]

Related to #734, #1057

While moving the subscription reconciler to pkg/controller I found the following bugs:

1. Subscription reconciler does not validate the internal data before attempting to reconcile. This results in fetch attempts of a resource named "".

2. Get a badly formatted error "Failed to update Subscription's status: status does not contain address" when reply is not addressable.

[shashwathi]

/assign