unparam lint (#16771)

* fixed: `identifier` is unused lint error

* make saveMultipleMembersT method saveMultipleMembers

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

model/config.go

@@ -3188,7 +3188,7 @@ func (o *Config) IsValid() *AppError {
 		return err
 	}
 
-	if err := o.MessageExportSettings.isValid(o.FileSettings); err != nil {
+	if err := o.MessageExportSettings.isValid(); err != nil {
 		return err
 	}
 
@@ -3631,7 +3631,7 @@ func (s *LocalizationSettings) isValid() *AppError {
 	return nil
 }
 
-func (s *MessageExportSettings) isValid(fs FileSettings) *AppError {
+func (s *MessageExportSettings) isValid() *AppError {
 	if s.EnableExport == nil {
 		return NewAppError("Config.IsValid", "model.config.is_valid.message_export.enable.app_error", nil, "", http.StatusBadRequest)
 	}