Fix lint for windows

Author: lunny

services/auth/sspi_windows.go

@@ -12,6 +12,7 @@ import (
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/models/avatars"
 	"code.gitea.io/gitea/models/login"
+	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"