Update UAA login_spec for generic http error
Update UAA login_spec for generic http error

[#113552877](https://www.pivotaltracker.com/story/show/113552877)

Signed-off-by: Shatarupa Nandi <3efeaa499e3e1d586e0cf648346ba222fe46816b@pivotal.io>

barthy1/bosh,barthy1/bosh,barthy1/bosh,barthy1/bosh