refactoring

weed/storage/needle/volume_version.go

@@ -3,8 +3,11 @@ package needle
 type Version uint8
 
 const (
-	Version1       = Version(1)
-	Version2       = Version(2)
-	Version3       = Version(3)
-	CurrentVersion = Version3
+	Version1 = Version(1)
+	Version2 = Version(2)
+	Version3 = Version(3)
 )
+
+func GetCurrentVersion() Version {
+	return Version3
+}