Don't raise Retry dialog in loader kickstart networking (#722276)
From: Radek Vykydal <rvykydal@redhat.comuser>
Instead, fail silently as in RHEL 5 and RHEL 6.0. Depending on whether
the network is up, user can be asked for networking later in UI step.
Offer the Retry dialog only in the UI step where it actually works
(don't for early networking, when fetching ks, or in kicktart).