setup: Fix an infinite redirect in a rare case

Created by: SunilMohanAdapa

Don't try to show setup view for login page. This happens under a rare circumstance that user does not usually face. If 'users' module has not been setup but we try to run first boot and last part of the firstboot process is not yet completed and when user is not already logged in, an infinite redirect happens.

Simply don't try to show setup view for login URL under any circumstance. This is similar to how firstboot middleware itself does not meddle with login URL.