fix: Fix default variable naming

README.md

@@ -6,7 +6,7 @@ Ansible role to install and configure graylog sidecars on Debian / Ubuntu / RedH
 
 ```yaml
 # Unique node id. Default uses '/etc/machine-id'
-node_id: 'file:/etc/machine-id'
+graylog_sidecar_node_id: 'file:/etc/machine-id'
 
 # Sidecar repository urls based on OS family
 sidecar_repo_urls:

defaults/main.yml

-node_id: 'file:/etc/machine-id'
+graylog_sidecar_node_id: 'file:/etc/machine-id'
 sidecar_repo_urls:
   "RedHat": "https://packages.graylog2.org/repo/packages/graylog-sidecar-repository-1-5.noarch.rpm"
   "Debian": "https://packages.graylog2.org/repo/packages/graylog-sidecar-repository_1-5_all.deb"