Data source ignored in Top hosts widget and too much data gets selected

Steps to reproduce:

1. Enable debugging for current user group.
2. Create a widget:
   1. Create an item column.
      1. Select Data = Item value.
      2. Select any item.
      3. Select History data = Trends.
      4. Click Add column.
   2. Click Apply.
3. Open the debug info of the widget.

Result:

SQLs like: SELECT * FROM history ... LIMIT 86401.

Expected:

1. SQLs like SELECT ... FROM trends.
2. LIMIT 1 instead of LIMIT 86401 in case when selecting from history table.