Update a variable to catch and report

Signed-off-by: Suguru Hirahara <did🔑z6MkvVZk1A3KBApWJXv2Ju4H14ErDfRGxh8zxdXSZ4vACDg5>

roles/custom/matrix_playbook_migration/tasks/validate_config.yml

@@ -101,7 +101,7 @@
     - {'old': 'synapse_admin_docker_image_registry_prefix_upstream_default', 'new': 'synapse_admin_container_image_registry_prefix_upstream_default'}
     - {'old': 'synapse_admin_container_uid', 'new': 'synapse_admin_uid'}
     - {'old': 'synapse_admin_container_gid', 'new': 'synapse_admin_gid'}
-    - {'old': 'synapse_admin_docker_repo', 'new': 'synapse_admin_container_self_build_repo'}
+    - {'old': 'synapse_admin_docker_repo', 'new': 'synapse_admin_container_image_self_build_repo'}
     - {'old': 'synapse_admin_container_self_build', 'new': 'synapse_admin_container_image_self_build'}
     - {'old': 'synapse_admin_container_self_build_repo', 'new': 'synapse_admin_container_image_self_build_repo'}
     - {'old': 'synapse_admin_public_endpoint', 'new': 'synapse_admin_path_prefix'}