sftpd: fix keyboard interactive test cases

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

internal/sftpd/sftpd_test.go

@@ -393,9 +393,13 @@ func TestInitialization(t *testing.T) {
 	sftpdConf.KeyboardInteractiveHook = "invalid_file"
 	err = sftpdConf.Initialize(configDir)
 	assert.Error(t, err)
+	sftpdConf.KeyboardInteractiveAuthentication = true
 	sftpdConf.KeyboardInteractiveHook = filepath.Join(homeBasePath, "invalid_file")
 	err = sftpdConf.Initialize(configDir)
 	assert.Error(t, err)
+	sftpdConf.KeyboardInteractiveAuthentication = false
+	err = sftpdConf.Initialize(configDir)
+	assert.Error(t, err)
 	sftpdConf.Bindings = []sftpd.Binding{
 		{
 			Port:             4444,