[FIX] mrp: fix start workorder

Commit https://github.com/odoo/odoo/pull/110550/commits/b347675c36cc5c3f54bf64f2e295d0afe9196be8
merges mo/wo scheduled & effective dates.

Later commit https://github.com/odoo/odoo/pull/128043/commits/62590fa7d742267421a42cbf654352cd5b7e048c
for 15.0 fixes the mo start date.

Unfortunately, forward ports breaks 16.4 & later:
starting a workorder unplan the subsequent ones.

closes odoo/odoo#157373

X-original-commit: 36e4a0c5f6b572f27fbfee5c3aa5fe291a6e76c3
Signed-off-by: William Henrotin (whe) <whe@odoo.com>
Signed-off-by: Jean-Francois Aubert (ajf) <ajf@odoo.com>

addons/mrp/models/mrp_workorder.py

@@ -592,11 +592,6 @@ class MrpWorkorder(models.Model):
             if wo.state in ('done', 'cancel'):
                 continue
 
-            if wo.production_id.state != 'progress':
-                wo.production_id.write({
-                    'date_start': fields.Datetime.now()
-                })
-
             if wo.product_tracking == 'serial' and wo.qty_producing == 0:
                 wo.qty_producing = 1.0
             elif wo.qty_producing == 0:
@@ -607,6 +602,11 @@ class MrpWorkorder(models.Model):
                     wo._prepare_timeline_vals(wo.duration, fields.Datetime.now())
                 )
 
+            if wo.production_id.state != 'progress':
+                wo.production_id.write({
+                    'date_start': fields.Datetime.now()
+                })
+
             if wo.state == 'progress':
                 continue
             date_start = fields.Datetime.now()