copr/frontend: Fix task conditionals

<nirik> but I did just hit something amusing... mizdebsk: on
roles/copr/frontend/tasks/main.yml the last play there... I don''t
think "when: False" does what you want. Did you want to disable that?
<nirik> since "False" is just a string, I think it will always
evaluate to True. :)

roles/copr/frontend/tasks/main.yml

@@ -49,6 +49,10 @@
   - copr
   - service
 
+  # FIXME mizdebsk 2018-09-07: copr-frontend package available in
+  # f28-updates and f28-infra is too old and it doesn't have
+  # pagure-events.service service - a newer copr-frontend version
+  # should be added to one of these tags.
 - name: enable and start pagure-events
   service: name=pagure-events enabled=yes state=started
   when: not 'pagure-events.service is missing in latest copr-frontend rpm in f28 repos'
@@ -56,13 +60,18 @@
   - copr
   - service
 
+  # FIXME mizdebsk 2018-09-07: This task is currently disabled because
+  # admin status should be treated as application data and does not
+  # need to be Ansible-managed.  If it really needs to stay in Ansible
+  # then 1) the task shoud be fixed not to report changes and 2) it
+  # should allow setting different admins for staging and production.
 - name: set up admins
   command: ./manage.py alter_user --admin {{ item }}
   become: yes
   become_user: copr-fe
   args:
     chdir: /usr/share/copr/coprs_frontend/
-  when: False
+  when: not 'admin status is application data, not config'
   with_items:
   - msuchy
   - sgallagh
@@ -70,10 +79,13 @@
   - nb
   - kevin
 
+  # FIXME mizdebsk 2018-09-07: This task is currently disabled because
+  # it is not idempotent - index rebuilding should probably be part of
+  # upgrade playbook, not deployment playbook.
 - name: rebuild indexes
   command: ./manage.py update_indexes
   become: yes
   become_user: copr-fe
   args:
     chdir: /usr/share/copr/coprs_frontend/
-  when: False
+  when: not 'index rebuilding is not idempotent'