Add 'setup-ssl' tag to matrix-nginx-proxy

So that it is possible to deal with Let's encrypt certificates when
targeting setup-ssl

roles/matrix-nginx-proxy/tasks/main.yml

@@ -11,6 +11,7 @@
   tags:
     - setup-all
     - setup-nginx-proxy
+    - setup-ssl
 
 - ansible.builtin.import_tasks: "{{ role_path }}/tasks/ssl/main.yml"
   when: run_setup | bool