Prevent use of quota for bogus configurations

This is a stop-gap measure for the hypothetical case of a service configuration that yields NULL quota values.

client/sql/21_bulk_geocoding_functions.sql

@@ -49,7 +49,7 @@ BEGIN
   RAISE DEBUG 'cdb_bulk_geocode_street_point --> query_row_count: %; query: %; country: %; state: %; city: %; street: %',
       query_row_count, query, country_column, state_column, city_column, street_column;
   SELECT cdb_dataservices_client.cdb_enough_quota('hires_geocoder', query_row_count) INTO enough_quota;
-  IF NOT enough_quota THEN
+  IF enough_quota IS NULL OR NOT enough_quota THEN
     RAISE EXCEPTION 'Remaining quota: %. Estimated cost: %', remaining_quota, query_row_count;
   END IF;