Bug 42066: Prevent 403 after an expired OPAC session

If a session has expired, the login form will get an empty CSRF token
and the login form will return 403

To recreate:
hit /cgi-bin/koha/sco/sco-main.pl
then hit /cgi-bin/koha/opac-main.pl
login
=> 403
Apply this patch, try again
=> Success

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Pedro Amorim <pedro.amorim@openfifth.co.uk>

C4/Auth.pm

@@ -275,15 +275,18 @@ sub get_template_and_user {
         }
 
         if ($kick_out) {
+            $session  = get_session("");
             $template = C4::Templates::gettemplate(
                 'opac-auth.tt', 'opac',
                 $in->{query}
             );
+            $template->param( sessionID => $session->id );
+
             $cookie = $cookie_mgr->replace_in_list(
                 $cookie,
                 $in->{query}->cookie(
                     -name     => 'CGISESSID',
-                    -value    => '',
+                    -value    => $session->id,
                     -HttpOnly => 1,
                     -secure   => ( C4::Context->https_enabled() ? 1 : 0 ),
                     -sameSite => 'Lax',