Fix for U4-5564

If umbracoUseSSL is set to true, change makes GetCurrentServerUmbracoBaseUrl() return HTTPS URL.  Also overrides ApplicationContext.Current.OriginalRequestUrl to use Port 443 instead of originally loaded port.
Yes, I've just referred to the config variable for which you can set an explicit base url.

The problem ultimately is that the first request that came in to your site was on non-ssl, and therefore your original request url was a non-ssl request.

This is why this baseUrl config section exists now. To avoid using that, you'd have to specify some urlrewriting rules at IIS level to ensure all requests are SSL so that that the first request would always be guaranteed to be SSL. The