Fix SSO on RHEL6

The new pam implementation needs the ask_secret to be answered as well.

Change-Id: I21f5da545d4fa26f816c4e25c88eccb09d4cfd56
Bug-Url: https://bugzilla.redhat.com/1102095
Signed-off-by: Vinzenz Feenstra <vfeenstr@redhat.com>