[FIX] sale_timesheet: add a domain on so line field for task

SO line partner should be the same as the
task cutomer. The so line field only appears
when customer is set, so it makes sense.

addons/sale_timesheet/models/project.py

@@ -56,7 +56,7 @@ class Project(models.Model):
 class ProjectTask(models.Model):
     _inherit = "project.task"
 
-    sale_line_id = fields.Many2one('sale.order.line', 'Sales Order Item', domain=[('is_service', '=', True)])
+    sale_line_id = fields.Many2one('sale.order.line', 'Sales Order Item', domain="[('is_service', '=', True), ('order_partner_id', '=', partner_id)]")
 
     @api.multi
     def write(self, values):