Ignore "WARNING: This DataObject does not appear to have been stored! Please store before you commit."

There are a lot of warnings like

[ubuntu32] 2020-07-15T16:40:47 - [DataObject.commit]: WARNING: This DataObject (a McdImgCalDark with filename: ) does not appear to have been stored! Please store before you commit.

even when running without a database. This pollutes everything, notebooks, logs, etc. This warning should be ignored.