Remove reference to become_user: root

This was the default anyway

ansible/roles/docker/tasks/netdata.yml

@@ -5,7 +5,6 @@
     owner: "{{ docker_user.name }}"
     mode: "{{ docker_compose_directory_mask }}"
   become: true
-  become_user: root
 
 - name: Install netdata compose file
   template:
@@ -16,7 +15,6 @@
     validate: /usr/bin/docker-compose -f %s config
   register: compose_file
   become: true
-  become_user: root
 
 - name: Cycle netdata container
   docker_compose: