[FIX] stock: set print_label on picking types

In a1f32fafa85b300e2d656a57797b8dbde6e3f065, various onchanges from the
picking types were changed into computes. However, the compute for the
`print_label` field was forgotten and never linked to its field.

closes odoo/odoo#158869

Signed-off-by: Arnold Moyaux (arm) <arm@odoo.com>

addons/stock/models/stock_picking.py

@@ -60,7 +60,7 @@ class PickingType(models.Model):
         compute='_compute_use_existing_lots', store=True, readonly=False,
         help="If this is checked, you will be able to choose the Lots/Serial Numbers. You can also decide to not put lots in this operation type.  This means it will create stock with no lot or not put a restriction on the lot taken. ")
     print_label = fields.Boolean(
-        'Print Label',
+        'Print Label', compute="_compute_print_label", store=True, readonly=False,
         help="If this checkbox is ticked, label will be print in this operation.")
     # TODO: delete this field `show_operations`
     show_operations = fields.Boolean(