Return nil from get_table_bounds if they cannot be calculated
Return nil from get_table_bounds if they cannot be calculated

CartoDB/cartodb,splashblot/dronedb,CartoDB/cartodb,splashblot/dronedb,CartoDB/cartodb,splashblot/dronedb,splashblot/dronedb,CartoDB/cartodb,splashblot/dronedb,CartoDB/cartodb