Fix ca_crl.pem path on unicorn

I'm not sure whether this changed in a recent puppet version, but I just ran into an error because the ca_crl.pem file wasn't being created where puppet-puppet expected it. I believe this is correct now because it's the same as the [identical passenger setting](https://github.com/puppetlabs-operations/puppet-puppet/blob/774847f5a7ffb0987d6ce65638f0810d93cb4a72/manifests/passenger.pp#L55). (should probably move that to params.pp since it's the same)