sync with previous repo

roles/matrix-client-hydrogen/tasks/validate_config.yml

@@ -0,0 +1,9 @@
+---
+
+- name: Fail if required Hydrogen settings not defined
+  fail:
+    msg: >
+      You need to define a required configuration setting (`{{ item }}`) to use Hydrogen.
+  when: "(vars[item] == '' or vars[item] is none) and matrix_client_hydrogen_container_image_self_build|bool"
+  with_items:
+    - "matrix_client_hydrogen_default_hs_url"