added old/new to validate_config.yml

roles/matrix-bridge-mautrix-googlechat/tasks/validate_config.yml

@@ -9,6 +9,14 @@
     - "matrix_mautrix_googlechat_public_endpoint"
     - "matrix_mautrix_googlechat_appservice_token"
     - "matrix_mautrix_googlechat_homeserver_token"
+- name: (Deprecation) Catch and report renamed settings
+  fail:
+    msg: >-
+      Your configuration contains a variable, which now has a different name. 
+      Please change your configuration to rename the variable (`{{ item.old }}` -> `{{ item.new }}`). 
+  when: "item.old in vars" 
+  with_items: 
+    - {'old': 'matrix_mautrix_hangouts_enabled', 'new': 'matrix_mautrix_googlechat_enabled'} 
 - debug:
     msg:
     - '`matrix_mautrix_googlechat_homeserver_domain` == {{ matrix_mautrix_googlechat_homeserver_domain }}'