install wireguard only if variable is set to true

host_vars/mewimeet.de.yml

@@ -21,4 +21,5 @@ web_server: true
 netdata: true
 
 # VPN
+wireguard: true
 wg_local_ip: 192.168.3.10/32

roles/server/tasks/main.yml

@@ -10,6 +10,9 @@
     when: netdata is defined and netdata == true
   - include_tasks: utilities/snmpd.yml
   - include_tasks: utilities/wireguard.yml
+    when:
+      - wireguard is defined
+      - wireguard == true
   - include_tasks: system_setup/cron.yml
   - include_role:
       name: base