Fix Hydrogen self check

Thanks to Julian for pointing this out

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

@@ -21,3 +21,10 @@
   tags:
     - setup-all
     - setup-client-hydrogen
+
+- import_tasks: "{{ role_path }}/tasks/self_check.yml"
+  delegate_to: 127.0.0.1
+  become: false
+  when: "run_self_check|bool and matrix_client_hydrogen_enabled|bool"
+  tags:
+    - self-check

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

@@ -1,7 +1,7 @@
 ---
 
 - set_fact:
-    matrix_client_hydrogen_url_endpoint_public: "https://{{ matrix_server_fqn_hydrogen }}"
+    matrix_client_hydrogen_url_endpoint_public: "https://{{ matrix_server_fqn_hydrogen }}/config.json"
 
 - name: Check Hydrogen
   uri: