Use file:// rather than puppet:// with the Logstash Puppet submodule

I am using https://github.com/elasticsearch/puppet-logstash as a git submodule in a project that does not use a Puppet server and would like to update the submodule with https://github.com/elastic/puppet-logstash/pull/205/ to allow referencing files. Can you recommend a safe way to include the PR into the pre-existing submodule.

Thanks,

@electrical can you comment here?