fix a couple of problems with erl_ssl_path fact

[costela]

Hi there,

This small PR fixes two small issues with the erl_ssl_path fact.
The first is pretty straightforward: avoid the .gsub call if we didn't actually get any data to mangle.
The second is a bit less clear-cut: drop the use of .with_env while calling erl. Newer versions of facter (>=3) AFAIK stopped supporting it (compare 2.x docs with 3.x docs) and it was unclear why we needed it in the first place. If I'm missing something and it is needed in some case, I'd be happy to find another workaround.

Cheers

[wyardley]

@costela couple things:

1. I should have asked for tests on the first go-round with this new fact. The test should be in spec/unit/facter/util/fact_erl_ssl_path.rb. Let me know if you need more help / guidance on this part. Also, until we get modulesync run (as part of the module moving to Voxpupuli), please manually run rubocop on the test to make sure you don't introduce any new rubocop warnings.
2. Voxpupuli generally likes the commits to be squashed (so rebase, fixup the other commits, and then force-push the branch).

[wyardley]

@costela ps - Feel free to chat in #voxpupuli on irc.freenode.net or Puppet Community Slack if you need help w/ any of this. I realize you're not the original person who submitted the change. Let me know if creating the tests will be a problem.

[costela]

FYI: I've moved this PR to a different branch, and github doesn't seem to support updating the source branch (just the destination branch). So I'll open a new one shortly, including tests and squashed commits.