server: Use default logging configuration instead of zap production one

This fixes problem where logs json changes format of timestamp.

etcdctl/ctlv3/command/snapshot_command.go

@@ -19,6 +19,7 @@ import (
 	"fmt"
 
 	"github.com/spf13/cobra"
+	"go.etcd.io/etcd/client/pkg/v3/logutil"
 	snapshot "go.etcd.io/etcd/client/v3/snapshot"
 	"go.etcd.io/etcd/pkg/v3/cobrautl"
 	"go.uber.org/zap"
@@ -48,7 +49,7 @@ func snapshotSaveCommandFunc(cmd *cobra.Command, args []string) {
 		cobrautl.ExitWithError(cobrautl.ExitBadArgs, err)
 	}
 
-	lg, err := zap.NewProduction()
+	lg, err := logutil.CreateDefaultZapLogger(zap.InfoLevel)
 	if err != nil {
 		cobrautl.ExitWithError(cobrautl.ExitError, err)
 	}