fix: add selling price validation on update item

(cherry picked from commit 327d067305)

erpnext/controllers/accounts_controller.py

@@ -3965,6 +3965,7 @@ def update_child_qty_rate(parent_doctype, trans_items, parent_doctype_name, chil
 						).format(frappe.bold(parent.name))
 					)
 	else:  # Sales Order
+		parent.validate_selling_price()
 		parent.validate_for_duplicate_items()
 		parent.validate_warehouse()
 		parent.update_reserved_qty()