Fix IHA with the new region_name key

ia change f2e72352b1376ce719614e9cad4e4c71a3f9c3d8 we did the following
in nova-base.yaml:
- nova::placement::os_region_name: {get_param: KeystoneRegion}
+ nova::placement::region_name: {get_param: KeystoneRegion}

But in the IHA script we looked for the os_region_name config key in the
placemenet ini section of nova.conf, which is now missing.
We need to adapt that script as well. Without this fix we'll error
out like this:
Oct 16 09:08:12 overcloud-novacomputeiha-0 dockerd-current[14673]:   File "/var/lib/nova/instanceha/check-run-nova-compute", line 147, in create_nova_connection
Oct 16 09:08:12 overcloud-novacomputeiha-0 dockerd-current[14673]:     region_name=options["os_region_name"][0],
Oct 16 09:08:12 overcloud-novacomputeiha-0 dockerd-current[14673]: KeyError: 'os_region_name'

Closes-Bug: #1798560

Change-Id: I8906145955ab6c444efdfa73beca073a62c26e26

extraconfig/tasks/instanceha/check-run-nova-compute

@@ -111,6 +111,12 @@ def create_nova_connection(options):
     if nova_endpoint_type in ['internal', 'public', 'admin']:
         nova_endpoint_type += 'URL'
 
+    if 'region_name' in options:
+        region = options['region_name'][0]
+    elif 'os_region_name' in options:
+        region = options['os_region_name'][0]
+    else: # We actually try to make a client call even with an empty region
+        region = None
     nova_versions = [ "2.23", "2" ]
     for version in nova_versions:
         clientargs = inspect.getargspec(client.Client).varargs
@@ -136,7 +142,7 @@ def create_nova_connection(options):
                                  None, # Tenant
                                  None, # Auth URL
                                  insecure=options["insecure"],
-                                 region_name=options["os_region_name"][0],
+                                 region_name=region,
                                  session=keystone_session, auth=keystone_auth,
                                  http_log_debug=options.has_key("verbose"),
                                  endpoint_type=nova_endpoint_type)
@@ -144,7 +150,7 @@ def create_nova_connection(options):
             # OSP >= Ocata
             # ArgSpec(args=['version'], varargs='args', keywords='kwargs', defaults=None)
             nova = client.Client(version,
-                                 region_name=options["os_region_name"][0],
+                                 region_name=region,
                                  session=keystone_session, auth=keystone_auth,
                                  http_log_debug=options.has_key("verbose"),
                                  endpoint_type=nova_endpoint_type)