Code review comment for lp:~therp-nl/openupgrade-server/7.0-deferred_steps

Thanks for the suggestion, I just committed it.

About the dropping of columns and tables, this is triggered in the unlink method of ir.model.fields and ir.model respectively. I checked the logs from when I crafted this branch and all problematic models were related to deprecated modules that were not going to be reinstalled on 7.0 (such as our module to process a tax increase which occurred last year).