ui: Addresses tab shows raw column name "what"

[pablofrelo]

In the stats window, the Addresses tab shows the header "what" (lowercase),
while Hosts, Applications, Ports and Users show the "What" header, which is
also translatable.

The Addresses tab uses "display_fields": "*"
(ui/opensnitch/dialogs/events/config.py, TAB_ADDRS), so the raw DB column
name is displayed instead of the COL_STR_WHAT alias used by the other tabs.
It's visible in English too, and it can't be fixed by translations.

Found while testing the Polish translation (#1673).

[aadrian]

@pablofrelo I opened #1681 for this.

The cause turned out to be in GenericTableModel.setModelColumns(), not display_fields. When a query returns a different number of columns, the model replaces the headers with the raw db column names. In the Addresses tab that happens whenever no ASN db is available, and in all stats tabs after you open a detail view and go back.

If you can, it would be great if you could test it with your Polish translation. All headers should stay translated, including after opening a host or an address and going back.