Merge pull request #33 from dr1nf3rn0/hotfix/pgpool2_exporter_make_error

Make error on Debian 11 with Go

Author: pengbo0328

pgpool2_exporter.go

@@ -28,7 +28,7 @@ import (
 	"fmt"
 	"math"
 	"net/url"
-	"os"
+	_ "os"
 	"regexp"
 	"strconv"
 	"sync"