Update validate_config.yml for migration: adopt a simpler description

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

roles/custom/matrix_playbook_migration/tasks/validate_config.yml

@@ -10,7 +10,7 @@
   ansible.builtin.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 }}`).
+      Please rename the variable (`{{ item.old }}` -> `{{ item.new }}`) on your configuration file (vars.yml).
   when: "item.old in vars"
   with_items:
     - {'old': 'matrix_vars_yml_snapshotting_enabled', 'new': 'devture_playbook_state_preserver_vars_preservation_enabled'}
@@ -331,7 +331,7 @@
       ansible.builtin.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 }}`).
+          Please rename the variable (`{{ item.old }}` -> `{{ item.new }}`) on your configuration file (vars.yml).
       when: "item.old in vars"
       with_items:
         - {'old': 'matrix_nginx_proxy_proxy_matrix_metrics_enabled', 'new': 'matrix_metrics_exposure_enabled'}
@@ -536,7 +536,7 @@
       The Google Hangouts service was discontinued on 1st of November 2022.
       The mautrix-hangouts bridge has been deprecated in the playbook since December 2024 and was completely removed from the playbook in February 2025.
 
-      Please change your configuration (`vars.yml`) to remove all `matrix_mautrix_hangouts_*` variables.
+      Please remove all `matrix_mautrix_hangouts_*` variables from your configuration file (vars.yml).
 
       You may also wish to uninstall the bridge manually. See `docs/configuring-playbook-bridge-mautrix-hangouts.md` for more information.
 
@@ -548,7 +548,7 @@
     msg: |-
       The Email2Matrix service has been superseded by the Postmoogle bridge for a long time now and was completely removed from the playbook in February 2025.
 
-      Please change your configuration (`vars.yml`) to remove all `matrix_email2matrix_*` variables.
+      Please remove all `matrix_email2matrix_*` variables from your configuration file (vars.yml).
 
       You may also wish to uninstall the bridge manually. See `docs/configuring-playbook-email2matrix.md` for more information.