satellite/metainfo/piecedeletion: enable connection pool

We want to enable connection pool for piece deletion to avoid
doing multiple SSL hanshakes to SN while massive deletion process.

Change-Id: Ic917e4eda304ee16a286926ef046fe9e38bf38ca

satellite/metainfo/piecedeletion/service.go

@@ -109,6 +109,8 @@ func NewService(log *zap.Logger, dialer rpc.Dialer, nodesDB Nodes, config Config
 		dialerClone.DialTimeout = config.DialTimeout
 	}
 
+	dialerClone.Pool = rpc.NewDefaultConnectionPool()
+
 	return &Service{
 		log:                log,
 		config:             config,