[FIX] project: default order of task type

Before this patch, the order of a project's task type (its columns)
were defined by a sequence. However, when you quick-create columns,
they have the same sequence value: 1 by default. This results in
weird behavior when you edit a task type (for example, by changing its
tooltips), the column is moved at the end.

By ordering by sequence and id, the behavior is more intuitive
as the colum doesn't move when you edit it.

addons/project/models/project.py

@@ -11,7 +11,7 @@ from odoo.tools.safe_eval import safe_eval
 class ProjectTaskType(models.Model):
     _name = 'project.task.type'
     _description = 'Task Stage'
-    _order = 'sequence'
+    _order = 'sequence, id'
 
     def _get_mail_template_id_domain(self):
         return [('model', '=', 'project.task')]