Add decorator expected_errors for v3 attach_interfaces

All v3 api should use expected_errors to prevent unexpected exception
raised. This patch add decorator expected_errors for v3 attach_interfaces.

This patch also remove update action. Let the wsgi return HTTPNotFound for
it.

Change-Id: Icefe9f9adfa7ad01bc3ab11dcb7c132702390d04
Merge "Add decorator expected_errors for v3 attach_interfaces"