Bug 1973479: Secret URLs not working when page submitted

Calling group_user_can_assess_submitted_views() when logged out throws
a warning so we need to check that we are logged in before calling
this function

Change-Id: Idd1034b2e0a86425e87069e3a78e2cb1f8b8207f
Signed-off-by: Robert Lyon <robertl@catalyst.net.nz>
(cherry picked from commit 445a9670)