Fixed issue where API call would fail if per_page or page parameters wer...

When trying to make an API call with per_page or page with a query and I was getting no data back from the API call. The issue was related to the fact that the Http->prepare method was adding the per_page/page iterators to the url before the http->send method added the query parameters to the url.

I changed the code to look for an existing ? before adding the query parm.