fix(horizon): allow deploy without defined cluster issuer
diff --git a/roles/horizon/vars/main.yml b/roles/horizon/vars/main.yml
index fd831c5..a1618ca 100644
--- a/roles/horizon/vars/main.yml
+++ b/roles/horizon/vars/main.yml
@@ -33,7 +33,7 @@
               initial_choice: "{{ (keystone_domains is defined) | ternary(keystone_domains[0].name, 'atmosphere') }}"
             idp_mapping: "{{ keystone_domains | default([{'name': 'atmosphere', 'label': 'Atmosphere'}]) | vexxhost.atmosphere.keystone_domains_to_idp_mappings }}" # noqa: yaml[line-length]
           raw:
-            OPENSTACK_SSL_NO_VERIFY: "{{ (cluster_issuer_type == 'self-signed') | ternary('True', 'False') | string }}"
+            OPENSTACK_SSL_NO_VERIFY: "{{ ((cluster_issuer_type | default('self-signed')) == 'self-signed') | ternary('True', 'False') | string }}"
             WEBSSO_KEYSTONE_URL: https://{{ openstack_helm_endpoints['identity']['host_fqdn_override']['public']['host'] }}/v3
             # yamllint disable-line rule:line-length
             LOGOUT_URL: https://{{ openstack_helm_endpoints['identity']['host_fqdn_override']['public']['host'] }}/v3/auth/OS-FEDERATION/identity_providers/redirect?logout=https://{{ openstack_helm_endpoints_horizon_api_host }}/auth/logout/