Skip systemd service management in check mode

Default behaviour has been changed in ansible 2.10, running this role in check
mode was failing with the following error:

fatal: [XXXXX]: FAILED! => {"changed": false, "msg": "Could not find the requested service node_exporter: host"}

See ansible/ansible#72721 and
ansible/ansible#68136 for more information.

Author: ctrlaltdel

handlers/main.yml

@@ -5,3 +5,5 @@
     daemon_reload: true
     name: node_exporter
     state: restarted
+  when:
+    - not ansible_check_mode

tasks/main.yml

@@ -32,5 +32,7 @@
     name: node_exporter
     enabled: true
     state: started
+  when:
+    - not ansible_check_mode
   tags:
     - node_exporter_run