title: when I created logstash offline pack, it dosen't contain the change
body: <p>I want to modify the logstash integration rabbitmq plugin and use it
  (<a href="https://github.com/logstash-plugins/logstash-integration-rabbitmq.git" rel="nofollow noreferrer">https://github.com/logstash-plugins/logstash-integration-rabbitmq.git</a>)</p>
  <p>I modified the inputs/rabbitmq.rb and confirmed that it works properly on my local.</p>
  <p>I created an offline pack to upload it to the server, but the modified contents are not applied to the offline pack.</p>
  <p>No errors when installing gem files or creating offline packs</p>
  <p>After installing as an offline pack, when I checked rabbitmq.rb (vendor/bundle/jruby/2.5.0/gems/logstash-integration-rabbitmq-7.1.0-java/lib/logstash/inputs/),
  the file modification time seems to have changed, but the modifications have not been applied.</p>
  <p>I don't know why it can't only be applied to offline packs
  How do I fix this problem?</p>