Fix Azure CloudSubnet missing address_prefix

Azure moved from a single static Subnet.addressPrefix to an array of
addressPrefixes in the newer API version.  The older API version would
return no addressPrefix causing a NoMethodError.

app/models/manageiq/providers/azure/inventory/parser/network_manager.rb

@@ -80,11 +80,13 @@ def cloud_networks
 
   def cloud_subnets(persister_cloud_networks, cloud_network)
     cloud_network.properties.subnets.each do |subnet|
-      uid = subnet.id
+      uid  = subnet.id
+      cidr = subnet.properties.address_prefixes.first
+
       persister.cloud_subnets.build(
         :ems_ref           => uid,
         :name              => subnet.name,
-        :cidr              => subnet.properties.address_prefix,
+        :cidr              => cidr,
         :cloud_network     => persister_cloud_networks,
         :availability_zone => persister.availability_zones.lazy_find('default'),
         :network_router    => persister.network_routers.lazy_find(subnet.properties.try(:route_table).try(:id))

config/settings.yml

@@ -16,7 +16,7 @@
       :storage_disk: "2017-03-30"
       :template_deployment: "2017-08-01"
       :virtual_machine: "2017-12-01"
-      :virtual_network: "2017-11-01"
+      :virtual_network: "2023-11-01"
     :blacklisted_event_names:
       - storageAccounts_listKeys_BeginRequest
       - storageAccounts_listKeys_EndRequest