update_city_point: replace ne.gn_ascii join with ne.name_en

Here "gn" appears to refer to GeoNames.org as a source. The fields field
`gn_ascii` was deprecated and finally removed in 2021:
nvkelso/natural-earth-vector#477

The deprecation issue recommends to replace the removed field with the
use of `name` (already used) and `name_alts` (which I assume refers to
local variants `name_fr`, `name_en`, ...), so I've included a check on
the English column.

layers/place/update_city_point.sql

@@ -23,10 +23,10 @@ BEGIN
           ne.name ILIKE osm.name_en OR
           ne.namealt ILIKE osm.name OR
           ne.namealt ILIKE osm.name_en OR
+          ne.name_en ILIKE osm.name OR
+          ne.name_en ILIKE osm.name_en OR
           ne.meganame ILIKE osm.name OR
           ne.meganame ILIKE osm.name_en OR
-          ne.gn_ascii ILIKE osm.name OR
-          ne.gn_ascii ILIKE osm.name_en OR
           ne.nameascii ILIKE osm.name OR
           ne.nameascii ILIKE osm.name_en OR
           ne.name = unaccent(osm.name)
@@ -84,4 +84,4 @@ CREATE CONSTRAINT TRIGGER trigger_refresh
     AFTER INSERT ON place_city.updates
     INITIALLY DEFERRED
     FOR EACH ROW
-    EXECUTE PROCEDURE place_city.refresh();
+    EXECUTE PROCEDURE place_city.refresh();