Hosts/host groups are erased from top 100 triggers filter after changing time period

Steps to reproduce:

1. Navigate to Reports -> Triggers top 100
2. Specify at least 2 host groups and/or hosts in filter
3. Press "Apply"
4. Switch to time selector tab and change time period
5. Switch back to "Filter" tab

Result:
Only one last host group and/or host is left if filter.

Expected:
Filter shouldn't change when changing time period.