add default for appliances_environment_vars

Author: sjpb

environments/common/inventory/group_vars/all/defaults.yml

@@ -8,6 +8,7 @@ appliances_cockpit_state: absent # RHEL cockpit installed but not enabled in gen
 #appliances_state_dir: # define an absolute path here to use for persistent state: NB: This is defined as /var/lib/state in inventory by the default Terraform
 appliances_mode: configure
 appliances_pulp_url: https://ark.stackhpc.com
+appliances_environment_vars: {}
 
 # Address(ip/dns) for internal communication between services. This is
 # normally traffic you do no want to expose to users.