make the sdk a separate module

The SFTPGo SDK now is at the following URL

https://github.com/sftpgo/sdk

Fixes #657

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

vfs/filesystem.go

@@ -3,8 +3,9 @@ package vfs
 import (
 	"fmt"
 
+	"github.com/sftpgo/sdk"
+
 	"github.com/drakkan/sftpgo/v2/kms"
-	"github.com/drakkan/sftpgo/v2/sdk"
 	"github.com/drakkan/sftpgo/v2/util"
 )
 

vfs/folder.go

@@ -6,7 +6,8 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/drakkan/sftpgo/v2/sdk"
+	"github.com/sftpgo/sdk"
+
 	"github.com/drakkan/sftpgo/v2/util"
 )
 

vfs/sftpfs.go

@@ -17,11 +17,11 @@ import (
 	"github.com/eikenb/pipeat"
 	"github.com/pkg/sftp"
 	"github.com/rs/xid"
+	"github.com/sftpgo/sdk"
 	"golang.org/x/crypto/ssh"
 
 	"github.com/drakkan/sftpgo/v2/kms"
 	"github.com/drakkan/sftpgo/v2/logger"
-	"github.com/drakkan/sftpgo/v2/sdk"
 	"github.com/drakkan/sftpgo/v2/util"
 	"github.com/drakkan/sftpgo/v2/version"
 )

vfs/vfs.go

@@ -15,12 +15,12 @@ import (
 
 	"github.com/eikenb/pipeat"
 	"github.com/pkg/sftp"
+	"github.com/sftpgo/sdk"
+	"github.com/sftpgo/sdk/plugin/metadata"
 
 	"github.com/drakkan/sftpgo/v2/kms"
 	"github.com/drakkan/sftpgo/v2/logger"
 	"github.com/drakkan/sftpgo/v2/plugin"
-	"github.com/drakkan/sftpgo/v2/sdk"
-	"github.com/drakkan/sftpgo/v2/sdk/plugin/metadata"
 	"github.com/drakkan/sftpgo/v2/util"
 )