Add bare_rock and scree to sql

layers/landcover/landcover.sql

@@ -14,6 +14,7 @@ CREATE OR REPLACE FUNCTION landcover_class(landuse VARCHAR, "natural" VARCHAR, l
          WHEN landuse IN ('farmland', 'farm', 'orchard', 'vineyard', 'plant_nursery') THEN 'farmland'
          WHEN "natural" IN ('glacier', 'ice_shelf') THEN 'ice'
          WHEN "natural"='wood' OR landuse IN ('forest') THEN 'wood'
+         WHEN "natural" IN ('bare_rock', 'scree') THEN 'rock'
          WHEN "natural"='grassland' OR landuse IN ('grass', 'meadow', 'allotments', 'grassland', 'park', 'village_green', 'recreation_ground') OR leisure='park' THEN 'grass'
          WHEN "natural"='wetland' OR wetland IN ('bog', 'swamp', 'wet_meadow', 'marsh', 'reedbed', 'saltern', 'tidalflat', 'saltmarsh', 'mangrove') THEN 'wetland'
         ELSE NULL