fixing issue with with not handling sign in requests

Previous code did not use realm attribute. So we could have cases like realm was set to https but `requireHttps` was set to false. in this case, when user was trying to sign in from browser url: https:// embeddedsts didn't handle that url and browser was stack with request like `http://localhost:44303/_sts....` instead of https as per realm setting

This allow to have two settings in web app - for http and https and it will just work without any complications.