Fix the build of the unicorn backend.

tasks/unicorn.yml

@@ -7,7 +7,7 @@
     template: src=nginx_unicorn.conf.j2 dest=/etc/nginx/conf.d/nginx_unicorn.conf
     notify: Restart nginx
 
-  tags: [ 'ruby', 'redmine', 'unicorn' ]
+  tags: [ 'ruby', 'redmine', 'unicorn', 'unicorn_nginx' ]
   when: ansible_distribution_version is version_compare('18.04', '==')
 
 - block:

templates/nginx_unicorn.conf.j2

@@ -7,7 +7,7 @@ upstream unicorn {
     # server unix:/tmp/.sock fail_timeout=0;
 
     # for TCP setups, point these to your backend servers
-    {% for i in 0, {{ unicorn_worker_processes - 1 }} %}
+    {% for i in range(0, unicorn_worker_processes - 1) %}
     server 127.0.0.1:{{ unicorn_listen_port + i }} fail_timeout=0;
     {% endfor %}
   }