Don't set date in set_state_done for issue1087

inventory.py

@@ -90,11 +90,9 @@ class Inventory(ModelWorkflow, ModelSQL, ModelView):
 
         for line in inventory.lines:
             line_obj.create_move(cursor, user, line, context=context)
-        self.write(
-            cursor, user, inventory_id,
-            {'state': 'done',
-             'date': date_obj.today(cursor, user, context=context)},
-            context=context)
+        self.write(cursor, user, inventory_id, {
+            'state': 'done',
+            }, context=context)
 
     def copy(self, cursor, user, ids, default=None, context=None):
         date_obj = self.pool.get('ir.date')