Open redirect in UserLoggedInRedirectResponse

[logicbomb]

https://github.com/NancyFx/Nancy/blob/master/src/Nancy.Authentication.Forms/FormsAuthentication.cs#L81

The method will redirect to a URL even if it isn't local in Nancy.Authentication.Forms.FormsAuthentication.UserLoggedInRedirectResponse

[grumpydev]

@logicbomb this should now be fixed in master if you can give it a whirl?

[logicbomb]

This did the trick, the redirect works as expected.

[grumpydev]

@logicbomb thanks for checking it .. I've just pushed 0.15.1 to nuget with this fix in