skip tasks if preinstalled

roles/jitsimeet/tasks/main.yml

@@ -9,6 +9,7 @@
   # import role webserver
   - import_role:
       name: webserver # required. The name of the role to be executed.
+    when: preinstalled == false or preinstalled is not defined
 
   # install software
   - include_tasks: prepare_system.yml

roles/jitsimeet/tasks/prepare_system.yml

@@ -10,11 +10,13 @@
   - name: jitsimeet | reload systemd
     systemd:
       daemon_reload: true
+    when: preinstalled == false or preinstalled is not defined
 
   - name: jitsimeet | import GPG key
     apt_key:
       url: "https://download.jitsi.org/jitsi-key.gpg.key"
       state: present # not required. choices: absent;present. Ensures that the key is present (added) or absent (revoked).
+    when: preinstalled == false or preinstalled is not defined
 
   - name: jitsimeet | add repository
     lineinfile:
@@ -23,6 +25,7 @@
       create: True
       backup: True
     notify: apt_update
+    when: preinstalled == false or preinstalled is not defined
 
   - name: jitsimeet | flush handlers
     meta: flush_handlers