close #657: limit mountain_peak's 'ele' tag to 10000 (#658)

* close #657: limit mountain_peak's 'ele' tag to 10000

* layers/mountain_peak/layer.sql: implement a more elegant 'ele' filter

layers/mountain_peak/layer.sql

@@ -45,7 +45,9 @@ $$
           ) DESC
       )::int AS "rank"
       FROM osm_peak_point
-      WHERE geometry && bbox AND ele is not null AND ele ~ E'^-?\\d+'
+      WHERE geometry && bbox
+        AND ele is not null
+        AND ele ~ E'^-?\\d{1,4}(\\D|$)'
     ) AS ranked_peaks
   WHERE zoom_level >= 7 AND (rank <= 5 OR zoom_level >= 14)
   ORDER BY "rank" ASC;