Bump node_exporter to version 1.6.1

- Update gitlab-org/build/omnibus-mirror/node_exporter
  from 1.6.0 to 1.6.1

Changelog: changed

Author: dependencies.io Bot

config/software/node-exporter.rb

@@ -18,7 +18,7 @@
 require "#{Omnibus::Config.project_root}/lib/gitlab/prometheus_helper"
 
 name 'node-exporter'
-version = Gitlab::Version.new('node-exporter', '1.6.0')
+version = Gitlab::Version.new('node-exporter', '1.6.1')
 default_version version.print
 
 license 'APACHE-2.0'