Fix yamllint-reported errors

roles/custom/matrix_playbook_migration/defaults/main.yml

@@ -62,4 +62,3 @@ matrix_playbook_migration_matrix_nginx_proxy_uninstallation_enabled: true
 
 # Controls whether this role will try to detect and clean up the /matrix/ssl files.
 matrix_playbook_migration_matrix_ssl_uninstallation_enabled: true
-