Fixed valdiation

roles/matrix-dynamic-dns/tasks/validate_config.yml

@@ -6,7 +6,7 @@
       You need to define a required configuration setting (`{{ item }}`).
   when: "vars[item] == ''"
   with_items:
-    - "matrix_domain"
+    - "matrix_dynamic_dns_domain"
     - "matrix_dynamic_dns_provider"
     - "matrix_dynamic_dns_mode"