inventory: change how iad domain is constructed.

We can't use things that are not in the facts cache for this.

Signed-off-by: Kevin Fenzi <kevin@scrye.com>

inventory/zzz-inventory.config

@@ -2,7 +2,7 @@ plugin: constructed
 strict: False
 compose:
 groups:
-    iad2: datacenter == 'iad2'
+    iad2: ansible_domain = 'iad2.fedoraproject.org'
 keyed_groups:
     - prefix: distro
       key: ansible_distribution