Use a viewport size of 1 when displaying a list of actions for the ok dialog

Having a size 0 viewport made the action invisible, forcing the player to use the Esc action.

Source/DiabloUI/selok.cpp

@@ -66,7 +66,7 @@ void UiSelOkDialog(const char *title, const char *body, bool background)
 	}
 
 	vecSelOkDialogItems.push_back(std::make_unique<UiListItem>(_("OK"), 0));
-	vecSelOkDialog.push_back(std::make_unique<UiList>(vecSelOkDialogItems, 0, PANEL_LEFT + 230, (UI_OFFSET_Y + 390), 180, 35, UiFlags::AlignCenter | UiFlags::FontSize30 | UiFlags::ColorUiGold));
+	vecSelOkDialog.push_back(std::make_unique<UiList>(vecSelOkDialogItems, 1, PANEL_LEFT + 230, (UI_OFFSET_Y + 390), 180, 35, UiFlags::AlignCenter | UiFlags::FontSize30 | UiFlags::ColorUiGold));
 
 	strcpy(dialogText, WordWrapString(body, MESSAGE_WIDTH, GameFont24).c_str());