roundcubemail update broke nginx setup

[Henning]

Hello,

I just upgraded my kolab 3.3->3.4 server, which is now running 
roundcubemail 1:1.1.0-0~kolab7 with a nginx server. Unfortunately this 
broke my nginx setup. In the apache config (functional), there are some 
new rewrite and expire directives, which I tried to include in my setup 
(below). Please help me out with this.

After login, which is successful, I get a "not found" error message on 
https://example.com/roundcubemail/dfe61d12a0cf0a0d/?_task=mail.

If I try to access manually 
https://example.com/roundcubemail/?_task=mail, the error message is
----------------------
REQUEST CHECK FAILED

Access to this service was denied due to failing security checks!

Click here to try again. <<-- 
https://example.com/roundcubemail/dfe61d12a0cf0a0d/?_task=mail
----------------------

The config section for roundcubemail and nginx is this:

    ##
     ## Kolab Webclient
     ##
     location /roundcubemail {
         index index.php;
         alias //usr/share/roundcubemail;

         client_max_body_size 30M; # set maximum upload size for mail 
attachments
         # NEW
         location /roundcubemail/public_html {
             if ($query_string ~ "^/(roundcubemail|webmail)"){
                 rewrite "^[a-f0-9]{16}/(.*)" /%/$1 break;
             }
         }

         location /roundcubemail/assets {
             expires 50h;
             gzip off;
         }
         # END OF NEW

         # Deny all attempts to access hidden files such as .htaccess, 
.htpasswd, .DS_Store (Mac).
         location ~ 
^/roundcubemail/(README(.md)?|INSTALL|LICENSE|CHANGELOG|UPGRADING)$ {
             deny all;
         }

         location ~ ^/roundcubemail/(bin|SQL|config|logs)/ {
             deny all;
         }

         location ~ 
^/roundcubemail/program/(include|lib|localization|steps)/ {
             deny all;
         }

         # enable php
         location ~ \.php$ {
                 fastcgi_split_path_info ^(.+\.php)(/.+)$;
                 fastcgi_pass unix:/var/run/php5-fpm.sock;
                 fastcgi_index index.php;
                 include fastcgi_params;
                 fastcgi_param PHP_ADMIN_VALUE "session.gc_probability=1";
         }
     }

Best regards,
Henning