Fix Net::HTTP#get() for ruby 1.8+

The doc states that this function returned two values in version 1.1 (ruby 1.6).
http://ruby-doc.org/stdlib-1.8.7/libdoc/net/http/rdoc/Net/HTTP.html#method-i-get

It now returns only the HTTPResponse. We return the data from it.

This fixes mco find --dm=puppetdb.