MySQL, Postgres, MSSQL: Only debug log when in development (#19239)

Found some additional debug statements in relation to #19049 that 
can cause memory issues.

Ref #19049

pkg/tsdb/sqleng/sql_engine.go

@@ -12,6 +12,8 @@ import (
 	"sync"
 	"time"
 
+	"github.com/grafana/grafana/pkg/setting"
+
 	"github.com/grafana/grafana/pkg/infra/log"
 	"github.com/grafana/grafana/pkg/tsdb"
 
@@ -418,7 +420,9 @@ func (e *sqlQueryEndpoint) transformToTimeSeries(query *tsdb.Query, rows *core.R
 
 			series.Points = append(series.Points, tsdb.TimePoint{value, null.FloatFrom(timestamp)})
 
-			e.log.Debug("Rows", "metric", metric, "time", timestamp, "value", value)
+			if setting.Env == setting.DEV {
+				e.log.Debug("Rows", "metric", metric, "time", timestamp, "value", value)
+			}
 		}
 	}