userportal,webadmin: XSRF token generation fix

- Fix token generation to use session id instead of passed
  in jsessionid cookie, as that value might be stale. This
  prevents a lot of 500 errors in the log due to automatic
  login.

Change-Id: I3e9a234bada73873f398d4220808f573810440dc
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1115918
Signed-off-by: Alexander Wels <awels@redhat.com>