Add setting for whether to allow converting town road to non-house types

See: 51e22617

src/table/settings/settings.ini

@@ -2221,6 +2221,14 @@ strhelp  = STR_CONFIG_SETTING_IGNORE_OBJECT_INTRO_DATES_HELPTEXT
 patxname = ""construction.ignore_object_intro_dates""
 post_cb  = [](auto) { InvalidateWindowClassesData(WC_BUILD_OBJECT, 0); }
 
+[SDT_BOOL]
+var      = construction.convert_town_road_no_houses
+def      = false
+str      = STR_CONFIG_SETTING_ALLOW_CONVERT_TOWN_ROAD_NO_HOUSES
+strhelp  = STR_CONFIG_SETTING_ALLOW_CONVERT_TOWN_ROAD_NO_HOUSES_HELPTEXT
+cat      = SC_EXPERT
+patxname = ""construction.convert_town_road_no_houses""
+
 [SDT_BOOL]
 var      = station.adjacent_stations
 from     = SLV_62