Add `matrix_client_cinny_config_homeserverList` variable

roles/custom/matrix-client-cinny/defaults/main.yml

@@ -143,9 +143,13 @@ matrix_client_cinny_path_prefix: /
 # Controls whether the self-check feature should validate SSL certificates.
 matrix_client_cinny_self_check_validate_certificates: true
 
-# config.json
+# Default homeserver URL to use in the `config.json` file.
+# See `matrix_client_cinny_config_homeserverList`.
 matrix_client_cinny_default_hs_url: ""
 
+# Controls the `homeserverList` value in the `config.json` file.
+matrix_client_cinny_config_homeserverList: "{{ [matrix_client_cinny_default_hs_url] }}"  # noqa var-naming
+
 # Default Cinny configuration template which covers the generic use case.
 # You can customize it by controlling the various variables inside it.
 #

roles/custom/matrix-client-cinny/templates/config.json.j2

@@ -1,6 +1,4 @@
 {
   "defaultHomeserver": 0,
-  "homeserverList": [
-    {{ matrix_client_cinny_default_hs_url | string|to_json }}
-  ]
+  "homeserverList": {{ matrix_client_cinny_config_homeserverList | to_json }}
 }