Fix some Puppet Lint errors

As mention in the subject, i've fixed some Puppet lint errors.

Regards,
Matthias
The example you provided looks like this:

      $_server = $server ? {
        'UNSET' => $::ntp::params::server,
        default => $server,
      }

Your code, looks like this:

    puppetdb_server => $manage_config ? {
       true    => $puppetdb_server,
       default => undef
       },

Note your indent on the last closing brace, its different from the style guide.