Removing DEL_ Objects in AOT

Issue - The DEL tables have not been deleted after unchecking the "Keep Update Objects 4.0" and "Keep Update Objects 4.1" from the Config tree.

Solution -
Disable "Keep upgrade objects" configuration key after upgrade is finished and customer confirms that all data was succesully upgraded. Disabling the key results in physical removal of DEL_ tables and fields from the database (not from the AOT)