Only allow primary domain for RS

Replace user addresses with usernames in the respective URLs

spec/requests/webfinger_spec.rb

@@ -15,10 +15,10 @@ RSpec.describe "WebFinger", type: :request do
           res = JSON.parse(response.body)
           rs_link = res["links"].find {|l| l["rel"] == "http://tools.ietf.org/id/draft-dejong-remotestorage"}
 
-          expect(rs_link["href"]).to eql("https://storage.kosmos.org/tony@kosmos.org")
+          expect(rs_link["href"]).to eql("https://storage.kosmos.org/tony")
 
           oauth_url = rs_link["properties"]["http://tools.ietf.org/html/rfc6749#section-4.2"]
-          expect(oauth_url).to eql("https://example.com/rs/oauth")
+          expect(oauth_url).to eql("http://www.example.com/rs/oauth/tony@kosmos.org")
         end
       end