change server address from string to a type

weed/storage/erasure_coding/ec_volume.go

@@ -3,6 +3,7 @@ package erasure_coding
 import (
 	"errors"
 	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/pb"
 	"github.com/chrislusf/seaweedfs/weed/storage/volume_info"
 	"math"
 	"os"
@@ -30,7 +31,7 @@ type EcVolume struct {
 	ecxFileSize               int64
 	ecxCreatedAt              time.Time
 	Shards                    []*EcVolumeShard
-	ShardLocations            map[ShardId][]string
+	ShardLocations            map[ShardId][]pb.ServerAddress
 	ShardLocationsRefreshTime time.Time
 	ShardLocationsLock        sync.RWMutex
 	Version                   needle.Version
@@ -69,7 +70,7 @@ func NewEcVolume(diskType types.DiskType, dir string, dirIdx string, collection
 		volume_info.SaveVolumeInfo(dataBaseFileName+".vif", &volume_server_pb.VolumeInfo{Version: uint32(ev.Version)})
 	}
 
-	ev.ShardLocations = make(map[ShardId][]string)
+	ev.ShardLocations = make(map[ShardId][]pb.ServerAddress)
 
 	return
 }