Fix openstack driver private address retrieval

In ansible 2.19, the template for retrieving the public(floating) address
of a molecule instance returns a NoneType value, which in turn evaluates
to False when compared to , which cause the private address of the instance
to never get picker up as fallback. This commit changes the condition to
not address | bool which in both case will evaluate to True if the retrieval
of the public ip failed.

Author: ednxzu

src/molecule_plugins/openstack/playbooks/tasks/server_addr.yml

@@ -17,7 +17,7 @@
 - name: Set to first addr if no floating
   ansible.builtin.set_fact:
     address: "{{ item.addresses[item.metadata.get('network', 'public')][0].addr }}"
-  when: address == ""
+  when: not address
 
 - name: Populate instance config dict
   ansible.builtin.set_fact: