Problem with graphs for guest user in v.1.6.3

[Vitaly]

1. Open Zabbix as guest (logout)
2. Open any Graph. Change a period to e.g. 1 Year - No changes. The graph does not update.
For logged user graphs work well.

[loshak]

Same problem was on 1.6.3.... fixed on ver. 1.6.4.