Previously, connect sidecars would be re-registered with consul every cycle
of Nomad's reconciliation loop around Consul service registrations. This is
because part of the comparison used `reflect.DeepEqual` on []string objects,
which returns false when one object is `[]string{}` and the other is `[]string{}(nil)`.
Unforunately, this was always the case, and every Connect sidecar service
would be re-registered on every iteration, which happens every 30 seconds.