puppetlabs-chocolatey does not propagate null source error correctly

Repro steps:

1. Install puppet agent.
2. Install chocolatey client
3. Install chocolatey module
4. Remove all <source> from the Chocolatey config file \ProgramData\chocolatey\config\chocolatey.config
5. Apply a manifest that installs a package like this:
   package { "7zip": ensure => present, provider => chocolatey, }

Expected error (this is what you get if you run the choco command directly on the command line):
Installation was NOT successful. There are no sources enabled for packages and none were passed as arguments.

Actual error:
Notice: Compiled catalog for win-lqdv0cfio2q.localdomain in environment production in 0.02 seconds
Error: Could not prefetch package provider 'chocolatey': undefined method `each' for nil:NilClass
Error: /Package[7zip]: Could not evaluate: undefined method `each' for nil:NilClass