Description of problem:
When setting manageiq to work with ovirt-engine-sdk [1], and performing a targeted refresh for a host, the action fails.

Version-Release number of selected component (if applicable):
master, based on commit 

How reproducible:
always

Steps to Reproduce:
1. Follow [1] and set manageiq to work with the ovirt-engine-sdk
2. Select a specific host and click on 'Refresh Relationships and Power State'

Actual results:
Action fails and the evm.log contains:
[----] E, [2017-05-09T10:27:57.235798 #18731:1097120] ERROR -- : [NoMethodError]: undefined method `detect' for nil:NilClass  Method:[rescue in block in refresh]
[----] E, [2017-05-09T10:27:57.236071 #18731:1097120] ERROR -- : /home/masayag/work/manageiq-master/plugins/manageiq-providers-ovirt/app/models/manageiq/providers/redha
t/infra_manager/refresh/parse/strategies/host_inventory.rb:139:in `block in host_inv_to_switch_hashes'
/home/masayag/work/manageiq-master/plugins/manageiq-providers-ovirt/app/models/manageiq/providers/redhat/infra_manager/refresh/parse/strategies/host_inventory.rb:135:in
 `each'
/home/masayag/work/manageiq-master/plugins/manageiq-providers-ovirt/app/models/manageiq/providers/redhat/infra_manager/refresh/parse/strategies/host_inventory.rb:135:in
 `host_inv_to_switch_hashes'
/home/masayag/work/manageiq-master/plugins/manageiq-providers-ovirt/app/models/manageiq/providers/redhat/infra_manager/refresh/parse/strategies/host_inventory.rb:44:in 
`block in host_inv_to_hashes'


Expected results:
Refresh should completed successfully. 

Additional info:
[1] Set ':use_ovirt_engine_sdk' to true in config/settings.yml

The action fails since collecting data for host in v4 doesn't retrieve the entire list of networks. Therefore when trying to find a network which is reported by the host's nic as configured on the host - no network is found.
This leads to the exception above.