Install reverse proxy sites only if necessary

roles/nginx/tasks/main.yml

@@ -21,6 +21,7 @@
     dest: /etc/letsencrypt/dhparam
 
 - name: Copy reverse proxy sites
+  when: nginx.reverseproxy_sites|length + nginx.redirect_sites|length > 0
   template:
     src: "nginx/sites-available/{{ item }}.j2"
     dest: "/etc/nginx/sites-available/{{ item }}"
@@ -30,7 +31,8 @@
     - redirect
   notify: Reload nginx
 
-- name: Activate sites
+- name: Activate reverse proxy sites
+  when: nginx.reverseproxy_sites|length + nginx.redirect_sites|length > 0
   file:
     src: "/etc/nginx/sites-available/{{ item }}"
     dest: "/etc/nginx/sites-enabled/{{ item }}"