fix issue with linktos in atom feeds discussed on mailing list

I know projection is still in beta, but this worked in rc9, and I might know what the problem is.

When the url for the event is generated for in the UI for the projection it seems it is using the sequential id for the projection rather than the sequential id in the original stream.

In my original stream I have the url http://localhost:2113/streams/Enhet-4361783b-8cec-4f3f-b9c8-50aab38d650e/2?embed=tryharder for an event and this is working in the UI for the stream.

In the category projection UI the same event get the url: http://localhost:2113/streams/Enhet-4361783b-8cec-4f3f-b9c8-50aab38d650e/85?embed=tryharder. As you can see the 2 after the stream id is changed to 85, and 85 is the number for that event in the stream.