Fix obtaining of service instance ip

On service instance creation step using service_instance module
we try obtain ip of instance by service network name.
This change adds one more possible way to obtain ip and
provides more detailed info in exceptional cases.

Change-Id: I472a17f02e1e208b3aa58d023b9eb72e936ffa98
Closes-Bug: #1292950
Merge "Fix obtaining of service instance ip"