Fixed empty canonicals

roles/web-app-pretix/config/main.yml

@@ -18,11 +18,12 @@ features:
   oauth2:           false   # Enable the OAuth2-Proy
   javascript:       false   # Enables the custom JS in the javascript.js.j2 file   
   universal_logout: true
-csp:                        
-  whitelist:        {}      # URL's which should be whitelisted           
-  flags:            {}      # Flags which should be set 
+csp:
+  whitelist:        {}      # URL's which should be whitelisted
+  flags:            {}      # Flags which should be set
 domains:
-  canonical:        {}      # Urls under which the domain should be directly accessible
+  canonical:
+     - "pretix.{{ primary_domain }}"
   aliases:          []      # Alias redirections to the first element of the canonical domains
 rbac:
   roles: {}