I know this is way late after the fact, but here is the way to enable http just for the RS Help pages, which allows the non-SSL help page link to work...
"- Expand the Reports site in IIS Manager, open the properties of the EN subfolder and uncheck the SSL setting. The EN folder contains the English help files so deselecting SSL on that folder will allow you to view help without SSL. You will need to modify other folders if you use help other than English."