Skip hostname validation for virtualization manager

[masayag]

When adding kubevirt provider with container provider at the same
request, there is no 'default' endpoint if the kubevirt provider is
added first. Therefore no need to check for hostname validation at that
point of time.

[masayag]

Verified by:

cat <<EOF | curl -X POST -H "Content-Type: application/json" -u "admin:smartvm" --data @- "localhost:3000/api/providers"
{
"name": "kubevirt_prov 		",
"zone_id": 1,
  "type": "ManageIQ::Providers::Openshift::ContainerManager",
"connection_configurations": [
     {
       "endpoint": {
         "role": "kubevirt",
         "hostname": "master",
         "port": 8443,
         "security_protocol": "ssl-without-validation"
       },
       "authentication": {
         "role": "kubevirt",
         "auth_key": "token"
       }
     },
     {
       "endpoint": {
         "role": "default",
         "hostname": "master",
         "port": 8443,
         "security_protocol": "ssl-without-validation"
       },
       "authentication": {
         "role": "bearer",
         "auth_key": "token"
       }
     }
   ]
}
EOF

Which returned:

{"results":[{"href":"http://localhost:3000/api/providers/131","id":"131","name":"kubevirt_prov","created_on":"2018-04-09T05:10:45Z","updated_on":"2018-04-09T05:10:45Z","guid":"04edaafd-a932-4610-b3f8-cd9752ccedd1","zone_id":"1","type":"ManageIQ::Providers::Openshift::ContainerManager","api_version":"v1","uid_ems":null,"host_default_vnc_port_start":null,"host_default_vnc_port_end":null,"provider_region":null,"last_refresh_error":null,"last_refresh_date":null,"provider_id":null,"realm":null,"tenant_id":"1","project":null,"parent_ems_id":null,"subscription":null,"last_metrics_error":null,"last_metrics_update_date":null,"last_metrics_success_date":null,"tenant_mapping_enabled":null,"enabled":true,"options":null}]}

While the same script fails without this PR with:
{"error":{"kind":"bad_request","message":"Could not create the new provider - undefined method `ipaddress?' for nil:NilClass","klass":"Api::BadRequestError"}}

[masayag]

@moolitayer @zeari please review.

[miq-bot]

Checked commit masayag@d71d556 with ruby 2.3.3, rubocop 0.52.1, haml-lint 0.20.0, and yamllint 1.10.0
1 file checked, 0 offenses detected
Everything looks fine. 🏆

[moolitayer]

This is identical to what @zeari did in #220. Looks good

[moolitayer]

LGTM 👍