fixes #42042

do not create group with region name if it is not given
Backport https://github.com/ansible/ansible/pull/42939

(cherry picked from commit d3f53b4b9f6167c359dae1069cb71eb10d00afc0)

changelogs/fragments/42042-inventory_with_no_region.yaml

@@ -0,0 +1,2 @@
+bugfixes:
+- plugins/inventory/openstack.py - Do not create group with empty name if region is not set

lib/ansible/plugins/inventory/openstack.py

@@ -254,7 +254,8 @@ class InventoryModule(BaseInventoryPlugin, Constructable, Cacheable):
         groups.append(cloud)
 
         # Create a group on region
-        groups.append(region)
+        if region:
+            groups.append(region)
 
         # And one by cloud_region
         groups.append("%s_%s" % (cloud, region))