Fixed nodata problem on datapoints not using it

nodata.go

@@ -105,6 +105,7 @@ func nodataDatapoints() (datapoints []Datapoint, err error) {
 			FROM
 				datapoint
 			WHERE
+				nodata_problem_seconds > 0 AND
 				NOT nodata_is_problem AND
 				extract(EPOCH from (NOW() - last_value))::int > nodata_problem_seconds
 			) AS subquery